American Revolutionary officer and Federalist politician who served (1795–1800) with distinction in the first two U.S. cabinets.

During the American Revolution, Pickering served in several capacities under General George Washington (Washington, George), among them quartermaster general (1780–85). In 1786, after taking up residence in Philadelphia, he helped resolve the dispute with Connecticut settlers over claims to Pennsylvania's Wyoming Valley and helped develop the town of Wilkes-Barre. Pickering served as Indian commissioner (1790–95), postmaster general (1791–95), secretary of war (1795), and secretary of state (1795–1800). He was dismissed from office by President John Adams (Adams, John) after a policy dispute.

During the administrations of Jefferson and Madison, Pickering led the Federalist opposition in Congress, serving as senator from Massachusetts (1803–11) and as a member of the House of Representatives (1813–17). Remaining friendly to England and fearing the power of Napoleon, he bitterly opposed the War of 1812 (1812, War of). After his retirement from Congress, he devoted himself to agricultural experimentation and education.