What was the problem for the United States after the Annexation of Texas? What was the main effect of this action?

Under the terms of the treaty, Mexico ceded to the United States approximately 525,000 square miles (55% of its prewar territory) in exchange for a $15 million lump sum payment, and the assumption by the U.S. Government of up to $3.25 million worth of debts owed by Mexico to U.S. citizens.

Explanation:There you go

Following the annexation, relations between the United States and Mexico deteriorated because of an unresolved dispute over the border between Texas and Mexico, and the Mexican–American War broke out only a few months later.

Explanation: