The pros of the Texas Annexation is that the Texans get to escape the debts. And the total people that voted for the annexation is 7,664 people, (Golly! That's a lot)
Not everybody voted for the annexation, 430 people only voted against the annexation. Another con about the annexation, is that the U.S. didn't want another state that has slavery which the U.S. Government was trying to abolish.