Existing comment:
The Jefferson Pier marks the first meridian of the United States and was originally established in 1793 on a line due south through the center of the White House at the intersection of a line west from the center of the Capitol. The original point was marked by a wooden stake and replaced by a stone pier in 1804. The monument was removed and replaced several times until finally being restored in 1889 under the direction of Colonel O. H. Ernst, Officer in Charge of Public Buildings and Grounds. The pier, a 2 foot square granite monument extending 2 feet above the ground remains today a point of curiosity with tourists who seldom understand its significance. The meridian of the United States was changed to the center of the dome old Naval Observatory in 1850, and finally replaced legally by the adoption the Greenwich (England) Meridian for both boundaries and navigation in 1912.
Subsequent to the re-establishment of the Jefferson Pier in 1889, the Office of Public Building and Grounds set a new monument, the Meridian Stone of 1890 in the center of Presidents Park approximately 459 meters north of and in the same meridian as the Jefferson Pier, but in a more protected area. This monument is marked by an 18 inch square granite post set flush with the ground.
The above was from http://geodesy.noaa.gov/PUBS_LIB/freedom_stands.html |