Lee was born in 1745 in Upper Marlboro in the Province of Maryland. He was the son of Thomas and Christiana Lee, a grandson of Philip Lee, and descended from the "Blenheim" Line of the Lee family of Virginia. Richard Lee I was his great-great-grandfather. His education was attained in the private schools of his native colony. On October 27, 1771, Thomas Sim Lee married Mary Digges, whose father was a prominent Maryland landowner. They had eight children;
During the Revolutionary War, he backed the patriot cause, and organized a local militia in which he served as colonel. Lee entered politics in 1777, serving as a member of the Maryland Legislature, a position he held two years. The Maryland Legislature elected Lee governor in 1779. He was reelected in 1780 and 1781. During his first tenure, issues regarding the war effort were dealt with. He won wide praise for his logistical abilities as governor. Lee consistently procured fresh troops and supplies for the Continental Army. George Washington was Lee's friend, and learning of the plan to pin down Cornwallis, Lee exerted all his energies to support the American troops. After completing his term, Lee left office on November 22, 1782. He then served in the Continental Congress in 1783 and 1784, and was a member of the State convention that ratified the U.S. Constitution in 1788. In 1792, Lee was again elected governor of Maryland. He was reelected to a second term in 1793, and to a third term in 1794. During his final tenure, the state militia was established, and the Whiskey rebellion was suppressed. Lee left office on November 14, 1794. Later that same year, he declined a seat in the U.S. Senate. He also declined a third tenure as governor in 1798.
Leader in the struggle for independence
Thomas Sim Lee was one of the participants of the Annapolis Convention in the mid-1770s, which produced a constitution for Maryland and transformed the colony into a state. On July 26, 1775 he was one of the signatories of the Declaration of the Association of the Freemen of Maryland, an influential statement in the Revolutionary War.
As Governor of Maryland, Thomas Sim Lee signed the Act on February 2, 1781, whereby the Maryland Legislature ratified the Articles of Confederation and Perpetual Union. As Maryland was the 13th and final state to ratify the Articles, the act established the requisite unanimous consent for the formation of a Perpetual Union of the states. Prior to this event, Maryland had held out and refused to ratify the Articles until every state had ceded its western land claims. After Governor Thomas Jefferson signed the Act of the Virginia legislature on January 2, 1781 to grant these concessions the way forward for Maryland was cleared. On this second day of February, a Friday, as the last piece of business during the afternoon Session, "among engrossed Bills" was "signed and sealed by the Governor, in the Senate Chamber, in the presence of the members of both Houses...an Act to empower the delegates of this state in Congress to subscribe and ratify the articles of confederation." The Senate then adjourned "to the first Monday in August next". The formal signing of the Articles by the Maryland delegates took place in Philadelphia at noon time on March 1, 1781. With these events, the Articles entered into force and the United States came into being as a united and sovereign nation.
Member of the Congress of the Confederation
In his post-governor career, Thomas Sim Lee represented Maryland as a delegate to the Continental Congress in 1783 and 1784. He also was a member of the house of delegates in 1787. He declined the opportunity to serve in the convention that drafted the Constitution of the United States, but served in the state convention that ratified the Constitution in 1788. Lee voted for Washington's second term as a Federalist presidential elector.
The contribution of his wife
Governor Lee's wife, Mary Digges Lee, responded to the need of the Revolutionary War troops from Maryland by rallying the women of Maryland to raise money in support of the war effort. She then established a correspondence with General George Washington, asking how these resources could be put to best use. General Washington responded suggesting that the money raised be put toward the purchase of much-needed shirts and black neck clothes for the troops in the Southern army. He expressed gratitude to Mrs. Lee for the "patriotic exertions of the ladies of Maryland in favor of the army". The couple was very active in patriotic activities during the Revolutionary War. They were also very committed to their religious and community ties. They founded the St. Mary's Roman Catholic Church in Petersville, Maryland.
After retiring from political life in 1794, Governor Lee focused his attention on his estate, Needwood, in Frederick County, Maryland, where he owned some two hundred slaves. Lee set up a winter home in Georgetown, near the nation's capital. Federalists frequented the home, which became a meeting place for them. Thomas Sim Lee was on the Board of directors of the Patowmack Canal, which was intended by George Washington to connect the Tidewater near Georgetown with Cumberland. The project, which started in 1785, was completed in 1802.
Death
Mary Digges Lee died on January 25, 1805 at the age of 60. Thomas Sim Lee remained a widower in Needwood until his death on November 9, 1819 at the age of 74 years. He was first buried at Melwood Park, his wife's family home. In 1888 his and the Melwood Diggeses' graves were moved to a common grave in Mt. Carmel Roman Catholic Cemetery near Upper Marlboro, Maryland.
Tribute
A bronze plaque commemorating his life has been placed on a house he built in 1790 on 3001–3009 M Street in the Georgetown section of Washington D.C.. The site is now referred to as the Thomas Sim Lee Corner.
