Texas Annexation - 1845
After Texas won its independence from Mexico, it became it’s own country for 10 years. People in the U.S. were divided over whether to annex Texas. Southerners wanted to add another slave state, but Northerners wanted to keep Texas out because they opposed slavery. Mexico still believed they had claims to Texas so many feared the annexation of Texas would lead to a war. To Mexico, the annexation of Texas was an act of war and Congress declared war on Mexico after fighting ensued in Texas over which river, the Nueces or Rio Grande, was the border. This was known as the Mexican - American War.