The Pennsylvania Medical Society is a democratic organization governed by its physician members, founded in 1848.

Others included New Jersey, 1766; Massachusetts, 1780; South Carolina, 1789; Delaware, 1789; Connecticut, 1792; Maryland, 1798; Georgia, 1804; New York, 1807; Rhode Island, 1812; Vermont, 1813; Michigan, 1819; Virginia, 1821; Tennessee, 1830; Wisconsin, 1841; and Alabama, 1846.

The Pennsylvania Medical Society was organized on April 11, 1848, at the Methodist Episcopal Church in Lancaster.

Today, at this location is an historical marker that reads:Founded April 11, 1848, at the First Methodist Episcopal Church on this site.

Its purpose was to foster the advancement of medical knowledge, relieve suffering, and promote the health of the community.