Pierre Charles L’Enfant (August 2, 1754– June 14, 1825) was a French architect, civil engineer, and urban designer best known for his 1791 plan for laying out the U.S. capital city of Washington, D.C.
From 1771 to 1776, L’Enfant studied at the Ecole des Beaux-Art in Paris where his father, a painter specializing in landscapes and military subjects, was an instructor. Thereafter, he enlisted as a volunteer in the American Continental Army, serving primarily in the capacity of draftsman and surveyor. L’Enfant provided drawings for the American army’s first training manual and, while stationed at Valley Forge, drew a portrait of General George Washington, who became an influential supporter of L’Enfant’s post-military career.  L’Enfant had attained the rank of Captain of Engineers by the time of the British surrender in 1781.
The following year, at the request of the French ambassador, Washington sent L’Enfant to Philadelphia (then the U.S. capital) to design a colonnaded pavilion for dancing and other entertainments in honor of the birth of an heir to Louis XVI. According to Benjamin Rush, the surrounding grounds were “cut into beautiful walks and divided with cedar and pine branches into artificial groves.”  L’Enfant established a successful civil engineering practice in New York City, which became the seat of the federal government in 1785, and was celebrated for his efficient and elegant renovation of the old city hall, where the first United States Congress met and Washington was inaugurated as president in 1789.  In July 1790, Congress authorized the building of a new capital city on the Potomac River. L’Enfant had already written to Washington the previous year asking to design “the Foundation of a city which is to become the Capital of this vast Empire.” Duly appointed, he developed a visionary plan for a great metropolis, borrowing ideas from the maps of various European cities provided to him by Thomas Jefferson, but reinterpreting Old World conventions according to American ideals.  Exploiting the existing topography, L’Enfant reserved the most commanding positions for “Grand Edifices” (principally, the “Congress House” and “President’s House”) and “Grand Squares. He connected these focal points by means of thirteen diagonally radiating avenues representative of the original colonies. The long vistas were to be punctuated by a series of landscaped circles and squares ornamented with fountains, columns, obelisks, and other monuments in memory of those who had contributed to the nation’s liberty and independence. Each of the states of the union was to take responsibility for “improving” one of the squares as an expression of its distinct identity. An underlying network of streets, laid out at right angles in a grid pattern, provided the connective tissue that unified the capital. 
A succession of clashes with the commissioners overseeing L’Enfant’s work resulted in his dismissal in 1792.  Nevertheless, his plan for the city of Washington remained a touchstone for the capital’s development into the late 20th century.  L’Enfant worked on a number of other projects that ended abortively as a result of their outsize ambition and expense, as well as the architect’s prickly personality. These include the city plan and hydraulic system for Paterson, New Jersey (1793), Robert Morris’s mansion in Philadelphia (1794-96), Fort Mifflin on the Delaware (1793-95), and Fort Washington on the Potomac (1814). 
- Philander D. Chase, ed., The Papers of George Washington, Revolutionary War Series, 90 vols. (Charlottesville: University of Virginia Press, 2008), 17: 129, ; Scott W. Berg, Grand Avenues : The Story of the French Visionary Who Designed Washington, D.C. (New York : Pantheon Books, 2007), 19-47, view on Zotero; H. Paul Caemmerer, Pierre Charles L’Enfant, Planner of the City Beautiful, The City of Washington (Washington, D.C.: National Republic Publishing Company, 1950), 1-67 view on Zotero.
- Caemmerer, 1950, 87-88, view on Zotero; see also Webster, 2008
- Berg, 2007, 64-70, view on Zotero; Caemmerer, 1950, 108-18, view on Zotero.
- Caemmerer, 1950, 127, view on Zotero.
- Berg, 2007, 105-13, view on Zotero; Kirk Savage, Monument Wars: Washington, D.C., the National Mall, and the Transformation of the Memorial Landscape (Berkeley, Los Angeles, and London: University of California Press, 2005), 29-30, view on Zotero; Pamela Scott, "‘This Vast Empire': The Iconography of the Mall, 1791-1848," in The Mall in Washington, ed. Richard Longstreth, Studies in the History of Art, Center for Advanced Studies in the Visual Arts, Symposium Papers, XIV (Washington, D.C.: National Gallery of Art, 1991), 37-45 view on Zotero; J.L. Sibley Jennings, Jr., "Artistry as Design: L’Enfant's Extraordinary City," The Quarterly Journal of the Library of Congress, 36 (1979): 231-37 ; Caemmerer, 1950, 147, 149, view on Zotero.
- Richard W. Stephenson, "A Plan Whol[l]y New": Pierre Charles L’Enfant's Plan of the City of Washington (Washington, D.C.: Library of Congress, 1993), passim, view on Zotero; Caemmerer, 1950, 150-65, view on Zotero; Herman Kahn, and Pierre L’Enfant, "Appendix to Pierre L’Enfant's Letter to the Commissioners May 30, 1800," Records of the Columbia Historical Society, 44/45 [37th separately bound book] (1942/43), 191-213, view on Zotero.
- Caemmerer, 1950, 169-215, view on Zotero.
- Michael Bednar, L’Enfant's Legacy: Public Open Spaces in Washington, D.C. (Baltimore: The Johns Hopkins University Press, 2006), passim, view on Zotero; Jennings, 1979, 242-62 view on Zotero.
- Ryan K. Smith, Robert Morris’s Folly: The Architectural and Financial Failures of an American Founder (New Haven: Yale University Press, 2014), 60-201 passim view on Zotero; Russell I. Fries, "European vs. American Engineering: Pierre Charles L’Enfant and the Water Power System of Paterson,NJ," Northeast Historical Archaeology, 4 (1974), 68-70 view on Zotero.