Following Mexico's defeat in the war, most of the former Alta California territory was ceded on 2 February 1848 to the United States, under the terms of the Treaty of Guadalupe Hidalgo. The new Mexico-United States border was established slightly to the north of the previous Alta-Baja border, and the terms Las Californias and Alta California were no longer formally used. The areas in North America acquired by the U.S. were designated as unorganized "territory" under a military governor, pending reestablishment of civilian control and organization.