What are three reasons that the United States had for refusing to annex Texas after it became independent?

Following Texas' successful war of independence against Mexico in 1836, President Martin van Buren refrained from annexing Texas after the Mexicans threatened war. ... His efforts culminated on April 12 in a Treaty of Annexation, an event that caused Mexico to sever diplomatic relations with United States.

Explanation:

answer; i believe that the correct answer is (chronological order);