American Philosophical Society


Well before the Declaration of Independence, in 1743 Benjamin Franklin (1706-90) and his friend the Quaker botanist John Bartram (1699-1777) established the American Philosophical Society in Philadelphia as a declaration of scientific independence from Great Britain’s scientific domination. The APS developed from a group of local intellectuals keen on expanding human knowledge to serve informally as the national academy of science and national library for a half century after 1790, when the United States capital moved to Philadelphia. Over time, the APS expanded into a multidisciplinary society and prominent institution as members applied their expertise to endeavors ranging from charting unknown territories in the nineteenth century to examining the ethics of scientific advancement in the modern world.

A color painting of Benjamin Franklin
Benjamin Franklin founded the American Philosophical Society with others in order to “promote useful knowledge.” It was an extension of his earlier intellectual club, the Junto. (Historical Society of Pennsylvania)

Founded in 1743, the APS was an extension of Franklin’s intellectual club the Junto and an answer to London’s Royal Society. Marking a departure from British science, the founding document of the APS asserted that because the American colonies had matured, intellectuals could employ insights from their North American experience to promote human knowledge. Franklin and Bartram designated Philadelphia as the most logical headquarters because of its location, its easy access by sea, and the vibrant bookish culture fostered by the Library Company of Philadelphia, the lending library Franklin founded in 1731. Philadelphia also had the benefit of Bartram’s unparalleled botanical knowledge, as he collected and identified species of plants found only in North America.

Franklin and Bartram organized the APS to promote advancement in all fields of science. They proposed that there should be no fewer than seven members: a physician, botanist, mathematician, chemist, mechanic, geographer, and natural philosopher, in addition to a president, treasurer, and secretary. Members would meet once a month to conduct experiments in brewing, navigation, and agriculture among other subjects. Yearly membership dues (a Spanish piece of eight) funded the cost of experiments and the publication of the society’s findings, both for distribution among society members and abroad.

The APS quickly became much more collaborative than independent as it became an important international link in the exchange of scientific information. Members such as Bartram maintained ties with their British counterparts and sent specimens overseas, even during the Revolutionary War. From its earliest days, the APS made scientific inquiry a matter of international diplomacy as it elected members from around the world. The first international member of the society, elected in 1768, was the French naturalist and cosmologist Georges-Louis Leclerc (1707-88), followed a year later by the Swedish botanist Carl Linnaeus (1707-78). As its first female member, inducted in 1789, the APS chose the president of the Imperial Academy of Sciences in St. Petersburg, Princess Yekaterina Dashkova (1743-1810).

Building a Reputation

A black and white illustration of David Rittenhouse seated at a telescope
The American Philosophical Society rose to prominence when Philadelphia-based astronomer and APS member David Rittenhouse’s observances on the transit of Venus were published in 1771. (Historical Society of Pennsylvania)

In 1769, a merger with another scholarly society in Philadelphia, the American Society for Promoting Useful Knowledge, gave the APS new vigor and initiated a series of scientific activities that solidified its mission. A crucial first step in establishing the APS as a reputable scientific authority occurred in the same year when David Rittenhouse (1732-96) observed by telescope the transit of Venus. His findings, with other observations around the globe, helped to determine the distance of Earth from the sun. Rittenhouse’s results were published in the APS’s Transactions of 1771 and distributed by Franklin across Europe, putting Rittenhouse’s findings on par with those of the Royal Society in London. In 1770, gifts from Thomas Penn (1702-75), members, and from scientific societies in Dublin and London established the APS Library.

In 1783, the APS sought to further secure its future by voting to build a headquarters, a task completed in 1789. Through a combination of members’ donations and a loan from Franklin, Philosophical Hall was constructed on Fifth Street adjacent to the Pennsylvania State House (later Independence Hall) under the direction of Samuel Vaughan (1720-1802), a friend of Franklin. Vaughan’s sense of style was also responsible at the time for gardens around Philadelphia, including that of the State House, and he designed the garden of another member of the APS: George Washington (1732-99) at Mount Vernon. With its new building, the APS also became a resource for public access to the sciences. Member Charles Willson Peale (1741-1827) housed his Philadelphia Museum at the APS from 1794 to 1811, and the University of Pennsylvania also used its space for five years beginning in 1789.

A black and white photograph of Philosophical Hall showing library extension on top
Philosophical Hall at Fifth and Chestnut Streets is the headquarters of the American Philosophical Society. The third story addition was constructed in 1890 and removed in 1949. (

During and following the 1790s, when Philadelphia served as capital of the United States, the APS played a significant role in scientific activities and innovations of the early nation. As U.S. president, APS member Thomas Jefferson (1743-1826) sent Meriwether Lewis (1774-1809) and William Clark (1770-1838) to Philadelphia to study with other APS members, including Dr. Benjamin Rush (1746-1813), to prepare for their cross-country expedition in 1804. The APS helped to sponsor the mission, and in return the explorers contributed a huge bank of new scientific knowledge on botany, zoology, geography, and ethnology from their travels. Just as their founder Franklin was a leading statesman as well as a scientist, and especially after the success of the Lewis and Clark expedition, APS members tied their research to the service of the state and the expansion of American power. For instance, Commander Matthew Fountaine Maury (1806-73), the “Pathfinder of the Seas,” played a key role in charting the geography of the sea to support an expanding American Navy. In 1862, however, Maury was expelled from the APS for joining the Confederate Navy.

The impact of the APS extended as its members of the APS consulted on the founding of other American scientific and cultural institutions, including the National Academy of Sciences, the Franklin Institute, and the Smithsonian Institution. Ophthalmologist Isaac Hays (1796-1879), a leading member of the APS who advanced a theory of natural selection before Darwin published it in The Origin of Species (1859), was among the founders of the American Medical Association in 1847. APS membership in the nineteenth century included such prominent scientists as Alexander von Humboldt (1769-1859), Charles Darwin (1809-82), the Swiss-born Louis Agassiz (1807-73) and his wife American-born Elizabeth Cabot Agassiz (1822-1907), Louis Pasteur (1822-95), and Thomas Edison (1847-1931). The scope of the APS also expanded to an additional field of scholarship in 1884 when, inspired by the creation of the American Historical Association, the society began to elect leading historians into its ranks and created a Committee on Historical Manuscripts to promote access to its own rich history.

Isaac Minis Mays, Secretary and Librarian

A color engraving of Library and Surgeons Halls on Fifth Street
The Library Company of Philadelphia operated out of Library Hall, directly across Fifth Street from Philosophical Hall, which was demolished in the nineteenth century. In 1958, APS purchased the lot and built a reconstruction of Library Hall to house the society’s own library. (Library Company of Philadelphia)

The work of producing manuscript catalogues and calendars of historical documents, as well as editing the Proceedings and Transactions of the APS was taken up by Hays’s son, Isaac Minis Hays (1848-1925), who served as secretary and librarian from 1897 to 1922. An energetic leader, Hays ushered the society into the twentieth century. He improved the quality of the APS library, expanded access to the library for researchers and the public, accomplished a fifteen-year project to bind and catalog the papers of Benjamin Franklin, and created the Franklin Medal to recognize excellence in both science and public service.

The APS continued its transition to a multidisciplinary scholarly organization under the leadership of biologist Edwin Grant Conklin (1863-1952), who served in a variety of APS offices leading to two terms as president in 1942-45 and 1948-52. In addition to members such as Margaret Mead (1901-78) and Albert Einstein (1879-1955), in the twentieth century the society expanded its membership from the humanities: poet Robert Frost (1874-1963), philosopher Isaiah Berlin (1909-97), poet Seamus Heaney (1939-2013), and historian Natalie Zemon Davis (b. 1928). By the early twentieth century, in a departure from the society’s early history of collaboration with the United States military and government, members included scholars whose research questioned institutional power over the individual and reflected on access to justice. They included a philosopher of ethics and human rights, Martha Nussbaum (b. 1947), queer theorists Eve Kosofsky Sedgwick (1950-2009) and Judith Butler (b. 1956), and post-colonial theorist Gayatri Chakravorty Spivak (b. 1942).

A black and white photograph of Paul Heyl and Lyman Briggs with their earth inductor compass and the Magellanic Premium award
The American Philosophical Society awards the Magellanic Premium for significant developments in the field of navigation, astronomy, or natural philosophy. It has only been awarded thirty-four times in over two hundred years. (Library of Congress)

These APS members and many others extended and elevated Philadelphia’s vibrancy, which initially made the city fit to host the society, to a truly international stage. In the second half of the twentieth century, the society also increased its physical presence in its home city. In 1959, across Fifth Street from Philosophical Hall, the APS opened Library Hall, a reproduction of an eighteenth-century structure that originally housed the Library Company of Philadelphia. In 1984 and 2000, the APS campus expanded to include two adjacent former bank buildings on Chestnut Street. Through its rich library and manuscript collection, research grants, and such prestigious prizes as the Magellanic Premium in navigation and astronomy, established in 1786, and the Barzun Prize in history the American Philosophical Society continued its mission of promoting useful knowledge. As affirmed by a mission statement adopted in 2008, the society’s activities sought to “reflect the founder’s spirit of inquiry, provide a forum for the free exchange of ideas, and convey the conviction of its members that intellectual inquiry and critical thought are inherently in the public interest.”

Brooke Sylvia Palmieri is a Philadelphia native living in London, working toward a Ph.D. at the Centre for Editing Lives and Letters at University College London. Her dissertation details the reading, writing, and publication habits of Quakers at the end of the seventeenth century and how they circulated their ideas from London to the British colonies in the West Indies and North America. (Author information current at time of publication.)

Copyright 2016, Rutgers University


Benjamin Franklin

Historical Society of Pennsylvania

The American Philosophical Association was an extension of an earlier intellectual club, the Junto, established by Benjamin Franklin. Formed in 1727, the Junto’s members discussed a broad range of topics including science. Franklin sought to expand this into a society for promoting and discussing science, based on the Royal Society of London. Franklin was keenly interested in education. His Junto group had also led to the creation of the Library Company of Philadelphia, the first lending library in the new colonies. Two years before the creation of the APS, he founded the Academy and College of Philadelphia (now the University of Pennsylvania), one of the first colonial colleges not dedicated solely to instruction of the clergy. Franklin hoped that the APS would appeal to the scientific minds in all of the thirteen colonies. Within a few decades of its creation, the APS had reached international renown.

John Bartram

Historical Society of Pennsylvania

John Bartram was one of the founders of the American Philosophical Society. Bartram was a self-educated botanist who traveled the continent collecting botanical specimens in the years prior to founding the APS. He wrote an immensely popular record of his travels, often simply called Bartram’s Travels. In 1728, Bartram established a botanical garden on his Kingsessing farm on the bank of the Schuylkill River, planting exotic species from around the world. The garden remains open to the public today and contains some of the oldest trees in the city. Bartram first suggested the formation of a scientific and philosophical society in letters to fellow botanist Peter Collinson of London. In 1743, he collaborated with Benjamin Franklin to form the APS

Map of the Lewis and Clark Expedition

National Geodetic Survey

With the Louisiana Purchase in 1803, the United States acquired a large swath of land that was largely unknown to science. President Thomas Jefferson appointed his personal secretary, Meriwether Lewis, and Kentucky military leader William Clark to lead an expedition across the new land and the Oregon Country to the Pacific Ocean. Jefferson was a member of the APS and sent Lewis and Clark to train with other APS members including physician Benjamin Rush. After their education in Philadelphia, the explorers departed from St. Louis, Missouri, and crossed lands unseen by non-Native Americans. The expedition took over two years and contributed new knowledge to many scientific fields. Lewis and Clark’s routes are shown on this map. They travelled together on the westbound route, but split into two groups on the return trip before reuniting in North Dakota.

David Rittenhouse

Historical Society of Pennsylvania

The American Philosophical Society began to gain respect in the scientific community early in its history. In 1769, astronomer David Rittenhouse described the transit of Venus, a rare phenomenon in which Venus passes between the Earth and the sun, for the American Philosophical Society. His observations were made at two observatories constructed for the event, one near his home in Norriton and one in the Pennsylvania State House garden (now Independence Hall). His findings were printed in the first issue of the APS's Transactions in 1771 and released internationally.

Rittenhouse was born just outside of the Germantown neighborhood of Philadelphia and held an early interest in astronomy and mechanical engineering. He built orreries, mechanical devices for studying the movement of the planets, for the University of Pennsylvania and Princeton University. He also used his mechanical skills to improve armaments for soldiers during the American Revolution and served as a member of the Pennsylvania Assembly and a delegate to the Pennsylvania Constitutional Convention in 1776. Rittenhouse was appointed president of the American Philosophical Society in 1791, a position he held until his death in 1796.

Magellanic Premium Is Awarded, 1922

Library of Congress

The American Philosophical Society distributes a number of prestigious awards for advancements in scientific fields, including the Magellanic Premium. Established in 1786 by John Hyacinth de Magellan, the Magellanic Premium is awarded for significant developments in the field of navigation, astronomy, or natural philosophy. It is the oldest scientific achievement award in the United States and had been awarded only thirty-four times as of 2016. This photograph shows the recipients from 1922, Lyman J. Briggs (left) and Paul R. Heyl, with their Earth inductor compass. This device advanced flight navigation and was later used by Charles Lindbergh in his 1927 transatlantic flight aboard the Spirit of St. Louis.

Philosophical Hall, 1929


The American Philosophical Society meets in Philosophical Hall at Fifth and Chestnut Streets, across from Independence Hall. The construction was approved in 1785, but because of funding shortages it was not completed until four years later, when the first meeting in Philosophical Hall was held on November 20, 1789. In order to raise funds for the building, space within it was rented out to other organizations including the University of Pennsylvania and Charles Willson Peale's Philadelphia Museum, a practice it continued until 1934. By the late nineteenth century, the American Philosophical Society had outgrown Philosophical Hall, largely because of the extensive American Philosophical Society Library. To remedy this, a third-story addition was constructed in 1890, seen in this photograph from 1929. It was removed in 1949 after the library was moved into a new building.

Library Hall

Library Company of Philadelphia

One of the American Philosophical Society's earliest endeavors was its library, donated to the organization by Thomas Penn. Over the years this grew into an extensive collection of over 350,000 books and thirteen million manuscripts on scientific history. The collection grew too large to be housed in the APS's Philosophical Hall even after a third story was added to the building in 1890. From 1789 until 1884, the lot directly across Fifth Street from Philosophical Hall was occupied by the Library Company of Philadelphia, a building shown in this illustration. It was demolished after the Library Company sold it and was replaced by a commercial building, itself demolished in the 1950s for Independence National Historic Park. In 1958, APS purchased the lot and constructed its new library building, a reproduction of the Library Company's original building on the lot.

Library Hall

Beyond My Ken via Wikimedia Commons

In 1959, across Fifth Street from Philosophical Hall, the American Philosophical Society opened Library Hall, a reproduction of an eighteenth-century structure that originally housed the Library Company of Philadelphia.

This photograph shows Library Hall in 2013.

In 1984 and 2000, the society's campus expanded to include two adjacent former bank buildings on Chestnut Street. Through its rich library and manuscript collection, research grants, and such prestigious prizes as the Magellanic Premium in navigation and astronomy, established in 1786, and the Barzun Prize in history the American Philosophical Society continued its mission of promoting useful knowledge.

Richardson and Benjamin Franklin Halls, Chestnut Street

The American Philosophical Society continued to expand down Chestnut Street through the twentieth century. In 1981, the society purchased the former Farmers’ and Mechanics’ Bank building at 425 Chestnut Street (center in this photograph). The bank was constructed in 1855 and features an ornate marble façade in the Italianate style. Farmers’ and Mechanics’ Bank merged with Philadelphia National Bank in the early twentieth century and continued to use the building until 1976. It was also, briefly, the home of the Independence Seaport Museum.

The American Philosophical Society renovated the building, now known as Benjamin Franklin Hall, and it now serves as auditorium space and a secure place for the APS Library’s collections. In 2000, the society purchased 431 Chestnut, shown here to the left of Benjamin Franklin Hall. The 1871 building once housed the Pennsylvania Company for Insurances on Lives and Granting Annuities. After the APS took control, it named the building Richardson Hall and connected its second floor to Benjamin Franklin Hall. Richardson Hall houses APS Museum staff offices.

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Time Periods



Related Reading

Carter, Edward C. One Grand Pursuit: A Brief History of the American Philosophical Society’s First 250 Years, 1743-1993. Philadelphia: APS, 1993.

Franklin, Benjamin. The Autobiography of Benjamin Franklin. New York: Dover Publications, 1996. See also: Autobiography of Benjamin Franklin.

Houston, Alan Craig. Benjamin Franklin and the Politics of Improvement. New Haven and London: Yale University Press, 2008.

Justice, Benjamin, ed. The Founding Fathers, Education, and “The Great Contest.” New York: Palgrave Macmillan, 2013.

Rosengarten, J.G. “The Early French Members of the American Philosophical Society” Proceedings of the American Philosophical Society 46 (Jan 1907) 87-93.

Smith, Murphy D. Oak from an Acorn: A History of the American Philosophical Society Library 1770-1803. Wilmington, Del.: Scholarly Resources, Inc., 1976.

Transactions of the American Philosophical Society, held at Philadelphia, for promoting Useful Knowledge. Philadelphia: Printed by William and Thomas Bradford, at the London Coffee-House, 1771.

Wulf, Andrea. The Brother Gardeners: Botany, Empire, and the Birth of an Obsession. London: Windmill Books, 2009.

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