Almost a decade after declaring its independence from Mexico in 1836, the Lone Star Republic of Texas became officially incorporated into the Unite States in 1845. A year later, the US invaded Mexico in what is known as the Mexican-American War. The war lasted just under two years, with both sides suffered approximately 15,000 casualties and losses. It ended in a victory for the US after the capture of Mexico City.
A peace treaty was signed which enforced Mexican Cession of Alta California and New Mexico to the US in exchange for $15 million. This video illustrates various battles of the war, the context in which they were fought, and the impact they had on the US in the years following.