I’ve been doing background research for my new project on geography and Asian American history, which I’m tentatively calling Barred Zones after the “Asiatic Barred Zone” established in 1917. Part of the article/chapter I’m writing involves systems of longitude and latitude—which fascinates my inner geek. While most people associate these systems with geography and think of them as, in a sense, “natural” because they locate places on the Earth, they are actually “social,” produced by people and institutions within specific historical contexts and circumstances, including politics, local, regional, national and international. A nice example demonstrating this point is the Washington meridian and its use in defining state and territorial borders within the United States in the late 19th century.
Today the international scientific community and most nations use the Greenwich meridian as the Prime Meridian, the meridian line defined as 0° 0′ 0″ longitude and used as a reference for all other values for longitude. Historically beginning in the 17th century France and most of non-British Europe used first the Ferro meridian (on the western most point of El Hierro, the western most island of the Canary Island chain) then the Paris Meridian as its prime meridian. Britain, however, beginning in 1721 used a series of meridians passing through the Greenwich Royal Observatory, which was established in 1675, as its longitudinal reference. The Greenwich Meridian re-calibrated in 1851 and set as the empire’s prime meridian was subsequently adopted by twenty-two nations including the United States as an international standard for longitude and the Universal Day at an 1884 conference in Washington, DC convened by President Chester A. Arthur. Notably, France abstained and continued using the Paris Meridian as its prime meridian into the early 20th century.
The United States had previously defined several prime meridians passing through Washington, DC. In his 1791 design for the city that became Washington, Pierre L’Enfant specified a meridian passing through the center of the building housing Congress (the U.S. Capitol had not yet been named or built). His plan also included a right triangle formed by the same building, the President’s house, and a statue of George Washington—corresponding respectively today to the Capitol, White House, and Washington monument. Its north-south side became known as the White House meridian.
In 1844, Congress relocated the Department of the Navy’s Depot for Charts and Instruments to near what is now 23d and E Streets NW in Washington, DC., building an astronomic observatory as part of the site—which was designated the U.S. Naval Observatory and Hydrographic Office in 1854 and is now known as the “Old Naval Observatory.” The Navy’s astronomical activities were assigned to a new Observatory (the “New Naval Observatory”) built further north on Massachusetts Avenue NW at 34th Street in 1893 while its previous building briefly housed a Naval Museum for Hygiene before the Naval Medical Hospital was build on its grounds in 1903 . Both observatory locations have served as prime meridians, the older passing through its actual observatory and the newer passing through the clock room of its building complex.
The meridian passing through the Old Naval Observatory, however, is more historically significant. In 1850, Congress voted to use it as the point of reference for “astronomical purposes” while using Greenwich for “nautical purposes.” In other words, while the Greenwich meridian was used to for navigating at sea, Washington meridian was used for geographical location and definition. Where previously state and territorial boundaries were largely defined by rivers and other natural geographic features, the meridian allowed longitude, which was abstract without necessary correspondence to physical terrain, to determine west/east boundaries of states. Latitude, which is equally abstract, had been used longer geographically, but longitude, in addition to a reference line, also required an accurate calculation of time at a level of precision that previously had been unavailable. Beginning in the 1860s, the boundaries of states and territories that by the early 20th century formed the interior West of the continental United States were marked by both latitude and longitude, the expression “west of Washington” used in the Congressional acts defining them referring to the Washington meridian.
The historical context is relevant as well as interesting. Many references to these state and territorial boundaries define them relative to the Greenwich meridian rather than the original Washington meridian. While their respective longitudes can be calculated, any rounding and/or dropping of minutes or seconds of arc introduce an imprecision that was not in the original—an issue for a system of absolute position. Equally significantly, geographic coordinate systems have been re-calibrated to different geodetic models of the earth. Since lines of latitude and longitude don’t correspond to actual physical features, the imprecision and recalibration literally shift their location “on the ground.” The western border of Kansas, defined as 25 degrees “west of Washington” in 1861, is not 25° 0′ 0″ degrees of longitude west of Washington, DC—or if it were, the border would differ by several hundred feet from its original location. This tension between actual location and the abstract precision of geographic coordinates gives new meaning to Dorothy’s famous line in the film The Wizard of Oz, “Toto, I don’t think we’re in Kansas anymore!”