What was in dispute between the united states and mexico before the outbreak of the mexican-american war? territory along the southern border of texas water rights along the rio grande borders for the newly acquired state of california territorial claims resulting from the louisiana purchase

The USA intervention in Mexican Territory , referred as the The USA intervention in Mexican Territory, referred as the Mexican-American War, was an armed conflict between Mexico and the USA between 1846 and 1848. It was caused by the expanding urge of the USA to the south; the first step was the creation of the so called Texan Republic, situation that separated the Mexican State of Coahuila and Texas. The other detonators of the war was the demands from the Mexican Government for retribution due to damages caused by the Texan independence War, and the trespassing of North-American forces into Mexican territory.

The answer to this question is:

territory along the southern border of Texas

it would have to be gasioline