US expansion was complicated by the division between "free" and "slave" states, which led to the Missouri Compromise in 1820. Likewise, Canada faced a division between French and English communities that led to the outbreak of civil strife in 1837. Mexico faced constant political tensions between liberals and conservatives, as well as the rebellion of the English-speaking region of Texas, which declared itself the Republic of Texas in 1836. In 1845 Texas joined the United States, which would later lead to the Mexican–American War in 1846 that began American imperialism. As a result of conflict with Mexico, the United States made further territorial gains in California and the Southwest.
US expansion was complicated by the division between "free" and "slave" states, which led to the Missouri Compromise in 1820 Likewise, Canada faced a division between French and English communities that led to the outbreak of civil strife in 1837 Mexico faced constant political tensions between liberals and conservatives, as well as the rebellion of the English-speaking region of Texas which declared itself the Republic of Texas in 1836. In 1845 Texas joined the United States, which would later lead to the Mexican–American War in 1846 that began American imperialism. As a result of conflict with Mexico, the United States made further territorial gains in California and the Southwest.