Mesilla County, Arizona Genealogy

Mesilla County was proposed in 1860 for a self-declared Arizona Territory. Four counties were proposed, Castle Dome, Dona Ana, Ewell, and Mesilla. A territorial government was created and maybe county governments. If governments were created, then records exist.

This Arizona territory requested recognition by the United States, but was rejected by Congress. So in 1861, they chose to be part of the Confederate States of America. However when Union forces took over in mid-1862, any governments still existing were shut down. The location for any county records has yet to be discovered.


 * 5 Apr 1860 - An unofficial convention held in Tucson declared the creation of the Territory of Arizona from the southern half of New Mexico Territory below 34 degrees north latitude and proposed 4 counties for the new territory: Castle Dome, Ewell, Mesilla, and Dona Ana. They also created a provisional constitution and established a government.  But the US Congress rejected the idea of Arizona becoming a territory, just as they had eight times before. So the proposed new territory was never officially created. However this time was different, because a government had been created for the intended Arizona Territory.
 * 16 Mar 1861 - Another unofficial convention met in Mesilla and declared that the territory formed the previous year was part of the Confederacy. An ordinance was written stating the reasons Arizona had seceded from the United States.
 * 28 Mar 1861 - Another convention held in Tucson ratified the Mesilla secession ordinance. Some government organization was made, including sending a delegate to the Confederate Congress.
 * 1 Aug 1861 - Confederate General John Robert Baylor, fresh from his victory at the Battle of Mesilla, made a proclamation declaring Arizona to be a Confederate Territory and appointed a government. A judicial district was formed for land around Mesilla and another one for land around Tucson.
 * 13 January 1862 - The Confederate Congress passed a bill declaring Arizona to be a Territory of the Confederate States of America. President Jefferson Davis signed the bill, which then became law.
 * 14 February 1862 - The Confederate law creating Arizona as a Territory became effective. Note: Fifty years later to the day, Arizona became a state in the United States of America.
 * 8 June 1862 - US General Carleton, having invaded from California driving the Confederate forces towards Texas, proclaimed in Tucson that the Territory of Arizona had been created by the United States and was devoid of all civil government.
 * 8 July 1862 - The last of the Confederate troops left Arizona Territory as Union troops from California and Colorado took over control.

See also Previous Jurisdictions to Land in Arizona showing dates the jurisdictions were created and maps. This will help in determining what jurisdiction your ancestor lived in and where the records are now located.