What caused the mexican war? did president polk provoke the texas boundary conflict in order to gain california or expand slavery, as war opponents such as abraham lincoln charged?

Mexican War Dictatorial Centralist government in Mexico commenced the war because of annexation of Texas. Mexico continued to claim in spite of the fact that the independent republic of Texas was established a decade before. However, some historians argue that the US started the war by annexing Texas and stationing an army in Rio Grande. Another interpretation was that the administration of US President James K. Polk forced Mexico to war to capture California and the Southwest.