History

Doņa Ana County, NM
In 1848, the Treaty of Guadelupe Hidalgo that ended the war with Mexico, should finally have established the boundaries between the United States and Mexico, including the huge area that was to be the Territory of New Mexico and Doņa Ana County. Unfortunately, the Mexican representatives and the United States group each had differently copied maps and talked at cross purposes.

People living in the tiny community of Doņa Ana, north of Las Cruces, thought they'd be living in the United States, because the town was east of the Rio Grande. Those who lived farther south in the community of La Mesilla, west of the Rio Grande, thought that they'd be Mexican citizens. People who chose to live in one country or the other, sometimes moved repeatedly since stories speed through the villages.

In 1850, the first house with a tin roof was built in La Mesilla. Soon after, La Mesilla became the capitol of the Territory. Doņa Ana County's western boundary was the California state line. It was a large area with a sparse population and remained huge until after the Civil War.