Banneker not only helped P Lefante draw up the city............he helped lay stones..........so they could build the new capital...........

Boundary Markers of the Original District of Columbia - Wikipedia

https://en.wikipedia.org/.../Boundary_Markers_of_the_Original_District_of_Columbia

2 Boundary Marker, along D.C./Maryland line, at 6980 Maple Street NW, Washington, D.C., with fence erected by the DAR. The Boundary Markers of the Original District of Columbia are the 40 milestones that marked .... On April 15, 1791, officials dedicated the south corner stone in an elaborate Masonic ceremony at a point ...

Mythology and legacy of Benjamin Banneker - Wikipedia

https://en.wikipedia.org/wiki/Mythology_and_legacy_of_Benjamin_Banneker

According to accounts that began to appear during the 1960s or earlier, a substantial ... Several such urban legends describe Banneker's alleged activities in the Washington, D.C. area ..... The plan contains in the last line of an oval in its upper left hand corner the words "By Peter Charles L'Enfant" (L'Enfant's adopted name) ...