What was the source of the conflict between the United States and México before they went to war?

Explanation:

the source was that Texas was a slave state and Mexico did really approve of it

concurrent jurisdiction is the ability to exercise judicial review by different courts at the same time, within the same territory, and over the same subject matter. for instance, a domestic violence matter may be heard in either a general civil court or a family court in the same county. whichever court actually exercises its jurisdiction first will do so exclusively.