During the Civil War, Mesilla briefly served as capital of the Confederate Territory of Arizona.

The first permanent settlement in Mesilla was established by 116 settlers from Chihuahua in the 1840s led by Pablo Melendres.

A small group of citizens, unhappy at being part of the United States, decided to move south of the border.

By 1851, the attacks caused the United States to take action to protect its people just to the north of the border, in the Mesilla Valley.

This boundary dispute, which was officially caused by a map error, was resolved in 1853 with the Gadsden Purchase.

Mesilla served as the capital of the Confederate Territory of Arizona in 1861–1862 and was known as the "hub", or main city for the entire region.

The area attracted such figures as Billy the Kid, Pat Garrett and Pancho Villa.

[11] In 1881, the Santa Fe Railway was ready to build through the Gadsden Purchase region of the country.

[12] In 2008, the Roman Catholic parish church of San Albino was raised to the status of minor basilica by the Holy See.

Demolition started in October 2013 and rebuilding ending in May 2014 for the annual "Cinco de Mayo" celebration.

According to the United States Census Bureau, the town has a total area of 6.7 square miles (17.4 km2), all land.