Answer: The desire to maintain a good relationship with Mexico.
Step-by-step explanation:
This is an exception because most Americans did not want to annex Texas because of the fear of war with Mexico, not because they wanted to maintain a good relationship with Mexico.
other reasons might be:
Fear of war with Mexico, which still considered Texas to be its territory
Concerns about the potential impact on slavery and the balance of power between free and slave states
Economic considerations, such as the potential cost of defending and developing the new territory
The belief that it would be better to focus on internal issues and territorial expansion in other areas
The desire to maintain a good relationship with Mexico