Statement of Significance (as of designation - January 12, 1965):
Since 1789 this two-story late-Georgian brick building has housed the fortnightly meetings of one of America's oldest and most honorable learned societies. The organization traces its origins to 1743, when Benjamin Franklin publicly urged the creation of an institution to stimulate interest in learning. Over the years the Society has counted America's intellectual elite among its members. Thomas Jefferson was one, and at his urging, the records of the Lewis and Clark Expedition are preserved in the Hall. The Society's journal, "Transactions", continues as the country's oldest scholarly periodical.