The New Mexico Territory was expanded in 1853 with the Gadsden Purchase. There were several proposals looking at separating the land into two territories. Most of the proposals were related to whether the government in Santa Fe, New Mexico could be effective in administering the southern portions of the large territory. In January 1857 a bill was introduced to the United States House of Representatives, but it was defeated on the grounds that the population was still too small. The real controversy was caused by the perception that the territory was controlled by southern sympathizers who were interested in expanding slavery. New Mexico tried again in 1858 suggesting a north south border along the 109th meridian.
When the Civil War started the territory was strongly in favor of the Confederacy. It held Territorial secession conventions in Mesilla and Tucson in March 1861. They adopted secession and set up a Provisional Confederate Territory of Arizona, and sent a petition to the Confederate Congress for admission. They elected Granville H Oury as a delegate to the Confederate Congress, and he drafted the legislation which would organize the Territory of Arizona. The legislation passed the Confederate Congress January 13th 1862, and signed into law by Confederate President Jefferson Davis on February 14th 1862.