 Briggs named the meridian the Washington Meridian, likely because the meridian passed near his offices in the community of Washington, Mississippi.The Washington Meridian runs north on a longitude of 91°09′36″W from the base line, which is the Mississippi–Louisiana border at latitude 31° north.The Washington Meridian is the basis of cadastral surveys in southwestern Mississippi, south of the Choctaw Meridian base line and west of the territory of the Saint Stephens Meridian.