What caused the war? (Short term and Long term causes) Short term: Killed AmericansLong term: Annexation of Texas, Invaded Us territory, refused to recognize the annex of texasWhat strategies were used by the United States to fightthe war? They sent John Slidell to negotiate an agreement where the Rio Grande would be the southern border of Texas and he was instructed to offer over $20 million for California, offered 5 million for the province of New Mexico and also sent a Marine Corps lieutenant to revolt against the mexican authority. He ordered General Taylor to march 3,000 troops in order to defend the Rio Grande What was the end result of the war? (Hint: Treaty of Guadalupe-Hidalgo)Treaty of Guadalupe-Hidalgo declared Mexico’s official surrender and sold the regions of New Mexico and upper California to the United States. Mexico also recognized the Rio Grande as America’s southern boundary. It give US opportunity to expand their sea.