Texas HistoryToday in Texas History: Compromise of 1850 Sets Boundary Between Texas and New Mexico

Four years before the U.S. annexed the Republic of Texas, President Mirabeau Lamar commissioned the Santa Fe Expedition aimed at staking a claim to western territory that encompassed a portion of the Santa Fe trail. The envoy was eventually captured by Mexican forces as they, too, claimed ownership of the territory.

In fact, Mexico officially disputed most of the territorial gains Texas was allotted by the Treaties of Velasco signed by Santa Anna after he was captured at the Battle of San Jacinto. But Texas was determined to control a portion of the trail to cash in on its trade.

Connecting Santa Fe, New Mexico to Franklin, Missouri, commerce and settlers trekked across the trail. After separating from Mexico and winning their independence, the Republic of Texas claimed ownership of territory stretching over to the 106th meridian and up into present-day Wyoming.

That land dispute bled into the Mexican War after Texas joined the union — the conflict that made a congressman from Illinois and his “Spot Resolution” famous. The Treaty of Guadalupe Hidalgo resulted in Mexico relinquishing its claims on the New Mexico territory but did not explicitly validate Texas’ claim.

When the time came for divvying the territory up into states, so too bubbled up the issue of slavery’s expansion. Texas, being a slave owning state and explicitly prohibiting its elimination by their legislature in its constitution, would expand the practice further into the western territory had it absorbed the New Mexico land. But New Mexico had maintained an anti-slavery position, and thus did not wish to be subsumed by its neighbor. The fact that Texas’ capitol lay hundreds of miles away also contributed.

For $10 million, the disputed land was handed to the U.S. government and, years later, divvied out between the various states that would take their shape. But at the time, along with the settlement of Texas’ current boundaries and its permission to remain a slave state, California was admitted as a free state along with the passage of the Fugitive Slave Act.

This patchwork of legislation is known as the Compromise of 1850 and it successfully postponed a civil war, but only for a short time. Texas voters approved their relevant portion of the compromise by a three to one vote.

While not born overtly out of goodwill, the compromise, and the portion of land it awarded to Texas’ neighbor, set the Lone Star State’s modern-day boundaries.