The U.S. Courthouse had its beginnings as the proposed territorial capitol for New Mexico. In 1848 under the Treaty of Guadalupe Hidalgo, Mexico ceded what is now New Mexico, Arizona, California, Texas, and portions of Colorado, Utah and Nevada, to the United States. The New Mexico territorial government was established two years later. In 1851 Congress appropriated ＄20,000 and in 1854 an additional ＄50,000 to construct a "state house" on what is now Federal Plaza.