As I was riding around the campus of George Washington University on this lunchtime bike ride, I happened upon a marker that I hadn’t seen before. As I would come to find out, it is The American Meridian Memorial. Located on a small bluff near the corner of 24th and H Streets (MAP) in northwest D.C.’s Foggy Bottom Neighborhood, it was once considered by some to be the center of the world, establishing a geographical line that separated the Eastern and Western hemispheres.
Prior to 1850, different countries measured longitude from different meridians. Because there was no agreement for a prime meridian, the way there is with latitude and the Equator, prime meridians and associated maps were identified in Greenwich, Paris, Rome, and various other European centers. American navigators tended to use either the French meridian at Paris or the British meridian at Greenwich.
Beginning in 1850, the United States established and began to measure distance from the American Meridian. The Federal government officially used this line, which ran along 24th Street, to measure distances on land, survey the West, coordinate the nation’s clocks, and record the start of new days.
However, few navigators at that time adopted the American Meridian, as they owned charts that gave distances relative to Paris or London, rather than 24th Street in D.C. In fact, the United States continued to utilize the Greenwich Meridian for longitude at sea. But land surveyors welcomed the ability to measure from the new American Meridian rather that a line that lay across a broad ocean. So as teams of American surveyors and mapmakers ventured steadily westward, those square boundaries of the Western states were all measured in appealing round numbers from the American Meridian.
Oregon would be the first to use the American Meridian in 1859 when it became a state. The southeastern border of the new state would be exactly 42 degrees West of the American Meridian. Colorado Territory in 1861 would be next to use the Meridian, establishing it’s eastern (27°W, Am) and western (34°W, Am) borders with the newly established meridian. The eastern border of Wyoming is exactly 27 degrees west of 24th Street, Arizona is 32 degrees west, and the Utah-Nevada border is 36 degrees west
The United States, via an act of Congress, officially abandoned the American Meridian in 1912, when it accepted the meridian at Greenwich as the international standard. Thus, the American Meridian was relegated to history. Today, the meridian marker is one of three reminders in D.C. of the evolution of cartography in this country. Meridian Hill Park was named for a stone obelisk that was erected there along the original prime meridian in 1804. The stone marker there is long gone, but the park named after it remains. And the third remnant of the pre-Greenwich Meridian age is The Zero Milestone, which is located on The Ellipse directly south of the White House. With the advancement of technology, one day the Greenwich Meridian may be a thing of the past as well.