William Pinkney (1764-1822), American lawyer and statesman, was born in Annapolis, Maryland, on the 17th of March 1764. He was admitted to the bar in 1786, and in 1788-1792 practised in Harford county. In 1788 he was a member of the state convention which ratified the Federal constitution for Maryland, in1788-1792and in 1795 of the House of Delegates (where in 1788 and 1789 he defended the right of slave-owners to manumit their slaves), and in1792-1795of the state executive council. In1796-1804he was a commissioner under article 7 of Jay's Treaty of 1794 to determine the claims of American merchants for damage through "irregular or illegal captures or condemnations," and during this time adjusted on behalf of Maryland a claim of the state to stock in the Bank of England. In May 1806, with James Monroe, then minister at London, he was commissioned to treat with the British government concerning the capture of neutral ships in time of war; in 1807-1811, after Monroe's return to America, he was resident minister in London. He was elected to the Maryland senate in September 1811, and from December 1811 to January 1814 was attorneygeneral of the United States. In August 1814 he was wounded at Bladensburg. He served in the National House of Representatives in January - April 1816, and in1816-1818was minister plenipotentiary to Russia and special minister to Naples, where he attempted to secure indemnity for the losses to American merchants by seizure and confiscation during the rule of Murat in 180 0. From 1820 until his death, at Washington, on the 25th of February 1822, he was a member of the United States Senate. He was a member of the conference committee on the bill for the admission of Maine and Missouri, which in its final form embodied what is known as the Missouri Compromise. Pinkney was a remarkably able lawyer and an orator of the old school.
See The Life of William Pinkney (New York, 1853) by his nephew, William Pinkney (1810-1883), who was Protestant Episcopal bishop of Virginia in 1879-1883; and Henry Wheaton, Some Account of the Life, Writings, and Speeches of William Pinkney (New York, 1828).