[2][4] It is regarded as a landmark in urban design and has inspired plans for other world capitals such as Brasília, New Delhi, and Canberra.

Jefferson sent L'Enfant a letter outlining his task, which was to provide a drawing of suitable sites for the federal city and the public buildings.

[11] L'Enfant was also provided a roll of maps by Jefferson depicting Frankfurt, Amsterdam, Strasbourg, Paris, Orléans, Bordeaux, Lyon, Marseille, Turin, and Milan.

[18] L'Enfant's "plan of the city intended for the permanent seat of the government of the United States..." encompassed an area bounded by the Potomac River, the Eastern Branch, the base of the escarpment of the Atlantic Seaboard Fall Line, and Rock Creek (named on the plan as Pine Creek).

[21][24][25][26] These "grand avenues" intersected with the north–south and east–west streets at circles and rectangular plazas that would later honor notable Americans and provide open space.

One branch of the canal would empty into the Potomac River south of the President's House at the mouth of Tiber Creek, which would be channelized and straightened.

[16][19][30][24] The President's House would be situated on a ridge parallel to the Potomac River north of the mouth of Tiber Creek, which L'Enfant proposed to canalize.

[25][31] A 400-foot-wide (122 m) garden-lined grand avenue containing a public walk (which became the National Mall) would travel for about 1 mile (1.6 km) along the east–west line.

[25][31] In 1793, a wooden marker was placed at the triangle's southwest corner (the intersection of the cross axis of the White House and the Capitol).

[37][40] After President Washington dismissed L'Enfant, Andrew Ellicott and his assistants continued the city survey in accordance with the revised plan, several versions of which were engraved, published, and distributed in Philadelphia and Boston.

[37][41] Ellicott's most complete plan, engraved and printed in 1792 by Thackera and Valance in Philadelphia, contained the names of L'Enfant's grand avenues and East Capitol Street as well as lot numbers and the depths of the channels of the "Potomak" River and the Eastern Branch.

In that year, he created a black and white copy of several portions of a manuscript plan of the federal capital city.

[46] Five years later, in 1887, the United States Coast and Geodetic Survey prepared a colored tracing of a manuscript plan.

[19][49] The message stated that the acting secretary of the treasury had directed that the tracing be produced for the purposes of preservation and reproduction.

[19][49] The assistant attorney's letter further stated that an office of the Corps of Engineers that was in charge of public buildings and grounds was holding the original plan, which had become so indistinct that it could not be accurately photographed.

The library's web page states that, in 1991, to commemorate the two hundredth anniversary of the manuscript map, the Library of Congress, in cooperation with the National Geographic Society, the National Park Service and the United States Geological Survey, published an exact-size, full-color facsimile[55] and an uncolored computer-assisted reproduction[21] of that map.

[17] The manuscript's upper left corner contains an oval that identifies the title of the map, followed by the words "By Peter Charles L'Enfant" written in a serif typeface that has the same alignment as does that in the United States Coast and Geodetic Survey's 1887 tracing.

[17] The library further states that, during the reproduction process, it was possible to record faint editorial annotations that Thomas Jefferson had made and which are now virtually illegible on the original map.

[17] However, others have contended that the named manuscript map that the library holds is actually an earlier draft that was hand-delivered to George Washington in June 1791.

[58] (L'Enfant's papers include an August 19, 1791, letter to President Washington that contains an "annexed map of dotted lines".

[59] The last line in an oval inscribed in the Plaza contains the words "By Peter Charles L'Enfant" written in a serif typeface.