Lincoln took his seat in Congress as the Mexican-American War was ending. Lincoln believed that the Mexican-American war was ____
You answered "all of the above," which is correct. Lincoln vigorously opposed the Mexican-American War, which he believed was motivated by politics and a thirst for the expansion of slavery to new territories. He was also convinced that the war was being waged unconstitutionally and said so in Congress. It is important to keep in mind that Washington politics at this time was dominated by the southern states. The northeastern and northwestern states were just beginning to increase their power and influence through the industrial and agrarian revolutions.