Who was Pierre Charles L'Enfant?

from CBS Sunday Morning "Almanac" - www.cbsnews.com/
August 2, 1754, 261 years ago today ... the day Pierre Charles L'Enfant was born in Paris.
Highly-educated, he traveled to America in 1777 and served as a civil engineer in the Revolutionary Army.
In 1791 President Washington commissioned him to plan the new capital city that was to rise on the banks of the Potomac River.
L'Enfant's design called for a rectangular street grid, intersected by a series of diagonal avenues named for the states.

The "dotted line" rendition of Pierre Charles L'Enfant's design of Federal City, dated 1791.

Library of Congress

He gave Congress a home on top of what came to be known as Capitol Hill -- while on the other side of town he placed the official home for the President, just north of the broad, park-like Mall.
L'Enfant died in 1825 at the age of 70, but his design for Washington, D.C., lived on, though with a few encroachments -- among them, a railroad station right in the middle of the Mall (the very station where President James Garfield would be assassinated in 1881).
To improve matters, Congress in 1901 created the McMillan Commission, a professional body that largely restored the Mall to L'Enfant's original design, and which also developed the riverbank land that later became home to the Jefferson and Lincoln Memorials.
Today, Washington, D.C.'s layout is still basically as L'Enfant envisioned it, with the National Mall serving as center stage for Fourth of July celebrations and other grand occasions.