The two statements that would work best as a thesis statement for your essay are:
- "The United States had valid reasons for going to war against Mexico in 1846."
- "The Mexican-American War was not justified."
These statements clearly take a position on the justification of the Mexican-American War, which aligns with the prompt asking for an evaluation and a definitive stance. The first statement supports the idea that the war was justified, while the second clearly argues against that perspective. Either statement can serve as a solid foundation for your essay.