In 1847, on this day the "Capitulation of Cahuenga" ended the fighting of the Mexican-American War in Alta California.
39th Parallel Part 2:
Capitulation of Cahuenga enlarges troubled UnionThe treaty was drafted in English and Spanish by José Antonio Carrillo, approved by American Lieutenant-Colonel John C. Frémont and Mexican Governor Andrés Pico on January 13, 1847 at Campo de Cahuenga. The later Treaty of Guadalupe Hidalgo ceded the whole of Mexico north of Tampico. As a result, California was split into two, with the creation of a new state of Colorado below the 37th. Chihuahua, Sonora, Coahuilia and Tamaulipas also entered the Union.
Victory in the US-Mexico War was a mixed blessing for the Union. Because the Wilmot Proviso sought to ban the extension of slavery into the new occupied states. Although the motion was defeated, the vote was taken on sectional (rather than party lines) and destroyed the unity of the Democratic Party. The Whig Party had already imploded over the slavery issue, and some senior political leaders formed the new Republican Party. They found success in 1856 when Frémont was elected to the Presidency. But by then America was completely unrecognizable from the country of 1847. An installment from 39th Parallel thread.