Pierre L’Enfant (1754-1825), French architect, engineer, and city planner. Pierre Charles L'Enfant was born in Paris and received his professional training in France. In 1777 his enthusiasm for the cause of American independence led him to volunteer in the Continental Army; his heroism as an officer of engineers earned him the admiration of George Washington. After retiring from the army in 1784, L'Enfant received several important commissions. He remodeled the old city hall (destroyed 1842) in Wall Street, New York City, for use of the first U.S. Congress in 1789.

Two years later L'Enfant was selected by Washington and Thomas Jefferson to draw up plans for a new national capital at Washington, D.C. L'Enfant's plan, essentially the city as it now stands, featured broad avenues radiating out from Capitol Hill, interrupted by a series of rectangular and circular parks, all overlaid with a rectangular grid pattern of streets. Construction was begun under his supervision but proved to be enormously expensive. In 1792 L'Enfant, who intractably disregarded costs and quarreled with public officials, was dismissed. He died in poverty in 1825 after a series of failed projects. Appreciation of his architectural vision grew, however, during subsequent generations. In 1889 the L'Enfant plan for the capital was resurrected, and in the 20th century almost all of his ideas were realized.