International Meridian Conference fixes the Greenwich prime meridian

Background. Prior to 1884, maritime countries used their own prime meridians. The International Geodetic Association recommended the Greenwich meridian as the international standard in 1883. The U.S. Congress authorized an international conference in 1882 to fix a common prime meridian for time and longitude, setting the stage for the diplomatic gathering in Washington.

Conference Proceedings. Held at the request of U.S. President Chester A. Arthur, the conference gathered 41 delegates from 25 nations in Washington, D.C. The primary subject was the choice of a common zero for longitude and time reckoning. The conference concluded that Greenwich Observatory best met the criteria for an international prime meridian.

Outcomes. The conference recommended the Greenwich meridian as the international standard for zero degrees longitude. This decision established the Greenwich meridian as the world standard for timekeeping and navigation for a century. The conference also hoped for British adherence to the Metre Convention as part of broader unification efforts.