Mexican-American War

The Mexican American War was a war between the two North American countries  Mexicoball and USAball.

History
In 1836, Republic of Texasball became independent. Since Mexicoball didn't recognize it,  USAball and  Republic of Texasball eventually allied against  Mexicoball. After the victory, Republic of Texasball was finally recognized by  Mexicoball and  USAball got various Southwestern states from this.