Mesilla’s historical significance is profound. The Gadsden Purchase, a pivotal 1854 land deal between the United States and Mexico, was negotiated and signed in Mesilla, shaping the map and future of the American Southwest. The town’s strategic location made it a crucial stop for the Butterfield Stagecoach and a center of commerce and travel in the region.

Mesilla’s Old West legacy runs deep. Legendary outlaw Billy the Kid was tried here for murder in the Mesilla courthouse, one of the few places where he faced justice. The story of Pat Garrett, the sheriff who famously tracked down and killed Billy the Kid, is also closely linked to Mesilla and its surrounding areas, adding to the town’s legendary status in Western lore.

At the heart of Mesilla stands the majestic Basilica of San Albino, built of adobe in 1855. This enduring landmark still hosts Masses in both English and Spanish, while outside, a poignant memorial honors parishioners who sacrificed their lives in combat.

The Old Doña Ana County Courthouse and Jail, constructed in 1850, is another significant site. Billy the Kid was tried here, and today, the building houses the Billy the Kid Gift Shop. It's a contributing property to the La Mesilla Historic District, listed on the National Register of Historic Places in 1982 .

The Barela-Reynolds House, dating back to around 1850, is one of the oldest and most historically significant structures in Mesilla. This adobe and brick building complex on the historic plaza once served as a store and residence, reflecting the town's commercial and residential history.

It is currently being developed into the Taylor-Mesilla Historic Site, a project aimed at preserving and showcasing Southern New Mexico’s rich cultural heritage for future generations.

Mesilla's commitment to preserving its heritage is evident through its designation as a National Historic Landmark and inclusion in the National Register of Historic Places. These recognitions highlight the town's efforts to maintain its historical character and ensure that its rich heritage is preserved for future generations.

Located just minutes from Las Cruces, New Mexico, Mesilla is an easy and rewarding day trip or overnight destination for those exploring the region, making it a perfect blend of history, culture, and contemporary charm.