This year marks the 170th anniversary of the annexation of Texas by the United States government. Although Texas militias had gained de facto independence from Mexico in 1836, negotiations between Mexico and the United States continued for another nine years as the Texas government attempted to work out a long-term strategy for Texas. Most Texans (especially the Anglo ones) wanted union with the United States, and American settlers looking to move to Texas also wanted union to ease emigration and legal issues. Moreover, American slave owners saw the opportunity to admit another slave state to the United States to counterbalance the addition of northern free states from the Louisiana Purchase.
In 1845, Congress approved annexation, significantly enlarging the size of the United States, but the annexation also brought with it many unresolved issues including ongoing border disputes with Mexico and simmering issues over the balance of slave states and free states in the electoral college and Congress.
