Prior to July 1, 1959, the United States used a length standard based on the 1893 Mendenhall Order, which fixed the yard at 3600/3937 m (or 0.9144018288 m). When the official United States yard was reduced to the length of 0.9144 m specified in the international agreement defining the International yard, the foot based on the old standard (one third of the pre-1959 yard, or 1200/3937 m) was retained under the name survey foot because some old maps had been surveyed in terms of this unit.