Pierre (Peter) L'Enfant was born in Paris, France on 2nd August, 1754 to a wealthy family of artists. He studied art under his father at the Royal Academy of Painting and Sculpture in Paris between 1771 and 1776.

He was the son of Pierre L’Enfant, “Painter in ordinary to the King in his Manufacture of the Gobelins.” The painter, whose wife was Marie Charlotte Leullier, daughter of a French military officer, had for his specialty landscapes and battle-scenes. Born at Anet, in 1704, on a farm which he bequeathed to his children, he was a pupil of Parrocel and had been elected an Academician in 1745. Some of his pictures are at Tours; six are at Versailles, representing as many French victories: the taking of Menin, 1744; of Fribourg, 1744; of Tournay, 1745; the battle of Fontenoy, 1745 (a favorite subject, several times painted by him); the battle of Laufeldt, 1747, where that young officer, destined to be Washington’s partner in the Yorktown campaign, Count Rochambeau, received, as we have seen before, his first wounds. The painter died a very old man, in the Royal Manufacture, 1787.

Pierre L'Enfant had a brother, Pierre Joseph, who died in 1758 and a sister.

In 1777 he left to join the American Revolutionary Army where he fought under George Washington. He'd watched American colonists declare their independence from England and fight for freedom. Now, he decided, it was time for him to act. He travelled to America with the Marquis De Lafayette. See also link.

Led by the same democratic spirit that inspired the colonists, L'Enfant became one of the first French volunteers to enlist in the Continental Army.  After the war ended, L'Enfant found work first in New York City remodeling the old City Hall for the meeting of the First Congress, then helping with the design of Philadelphia's Federal Hall.

Congress rewarded him by appointing him major of engineers in 1783. L'Enfant designed the medal and diploma of the Society of the Cincinnati, an association of former Revolutionary officers, and upon his return to Paris, he helped organize a French branch of the society.

L'Enfant returned to America in 1784 and settled in New York City in where he established himself as an architect. In March 1791 President Washington picked him to design the nation's new capital city. The plan of the city of Washington is based on principles employed by Andre Le Notre in the palace and garden of Versailles, where L'Enfant's father had worked as a court painter, and on Domenico Fontana's scheme (1585) for the replanning of Rome under Pope Sixtus V.

After a series of disagreements and personality clashes with the three commissioners appointed by Washington to oversee the project, he was dismissed by his mentor on 1st March 1792 after being responsible for removing without permission, the house of Daniel Carroll, an important resident in the city.. He was not paid for his services. L'Enfant later tried to obtain $95,500 for his work. Congress gave him what it deemed a suitable fee — about $3,800. He was offered a position as Professor of Engineering at West Point, in 1812, but declined. L'Enfant died in poverty on 14th June 1825 with personal effects valued at $44 and was buried at the farm of a friend, William Dudley Digges, in Prince George's County, Maryland.

In 1901, the McMillan Commission used the original design of L'Enfant as the cornerstone of its 1902 report, which laid out a plan for a sweeping National Mall. His adopted nation finally recognizing his genius, L'Enfant was re-interred in Arlington National Cemetery with a ceremony at the U.S. Capitol Rotunda, on April 22nd 1909, and honoured with a monument at his grave in 1911. He is buried in Arlington National Cemetery on a hill overlooking the city he designed.

Pictures of L'Enfant's grave in Arlington Cemetary: