Philip Barton Key (April 12, 1757 – July 28, 1815) was a Representative from the third district of Maryland, and later a United States federal judge. Unusually for a politician in the early United States, Key had been a Loyalist in the American Revolution. Born in Charleston, Cecil County, Maryland, Key pursued an academic course. During the War of Independence he served in the Maryland Loyalists Battalion as a captain. He fought with the British Army from 1777 to 1781, until he was captured by the Spanish in Pensacola, Florida with the rest of his battalion. He was kept as prisoner for a month in Havana, Cuba, before being paroled and sent to New York City until the end of the war.
After the war Key traveled to England to study law at the Middle Temple. In 1785 he returned to Maryland and read law to be admitted to the bar. He began practicing law in Leonardtown, Maryland in 1787, before moving to Annapolis in 1790, becoming a member of the Maryland House of Delegates from 1794 until 1799. He served as Mayor of Annapolis from 1797 to 1798. He returned briefly to private practice in Annapolis from 1799 to 1800.
On February 18, 1801, Key was nominated by President John Adams to a new seat on the United States circuit court for the Fourth Circuit, created by 2 Stat. 89. He was confirmed by the United States Senate on February 20, 1801, and received his commission the same day. He served as chief judge of that court from 1801-1802. Key’s service was terminated on July 1, 1802, with the abolition of the court.
Key then returned to private practice, from 1802 to 1807. He was a Counsel to Justice Samuel Chase during Chase’s Senate impeachment trial in 1805. During this time he built and lived in Woodley Mansion in Washington, DC.
In the fall of 1806 Key moved to Montgomery County, Maryland and became interested in agriculture. Between March 4, 1807 and March 3, 1813, he was elected as a Federalist to the Tenth, Eleventh and Twelfth U.S. Congresses. He also served as chairman for the Committee on District of Columbia during the Tenth Congress.
Key died in Washington County, D.C., and was interred on his estate, known as “Woodley”. Later, he was re-interred at Oak Hill Cemetery in Washington, D.C.