<P> The war ended on February 2, 1848, with the signing of the Treaty of Guadalupe Hidalgo . Mexico ceded claims to Texas, and the border was set at the Rio Grande . </P> <P> The expansion of the United States after the Mexican--American War led to tensions between the slave and free states as to how to maintain the balance between the opposing viewpoints . Texas had been admitted to the United States as a slave state, yet Texas claimed territory north of the 36 ° 30' demarcation line for slavery set by the 1820 Missouri Compromise . According to the annexation agreement, if Texas were to be subdivided into multiple states, those north of the compromise line would become free states . Following the conclusion of the Mexican--American War, Texas also tried to exert control over much of New Mexico . </P> <P> In an effort to avoid some states seceding from the United States, Congress passed the Compromise of 1850 . Texas gave up much of the western territories it had claimed in exchange for $10 million to pay off previous debts . </P> <P> Post-war Texas grew rapidly as migrants poured into the cotton lands of the state . German immigrants started to arrive in the early 1840s because of economic, social and political conditions in their states . In 1842, German nobles organized the Adelsverein, banding together to buy land in central Texas to enable German settlement . The Revolutions of 1848 acted as another catalyst for so many immigrants that they became known as the "Forty - Eighters ." Many were educated artisans and businessmen . Germans continued to arrive in considerable numbers until 1890 . </P>

Who lived in texas before it was annexed