Thursday Lesson Plan
ASSIGNMENT 4
20points
There are different theories to determine what caused the war between Mexico and the
United States. Read and examine some of the theories and for each theory, describe who would support that theory and why. (5 extra credit points)Write a one paragraph based on your opinion on the theory you most agree with.
Question:
What caused the Mexican-American War?
Theory 1: The United States wanted to connect the union from the Atlantic to the Pacific
Oceans regardless of who owned the land in between.
Theory 2: The southern states conspired to begin the war, because gaining this territory
would ensure the continuation of slavery.
Theory 3: “Manifest Destiny”, a view many Americans held at the time, implied that it was the
rightful destiny or duty of the U.S. to limitlessly expand its borders.
Theory 4: Religion; Since the United States was populated by a majority of Protestants and
Mexico by a majority of Catholics, it was assumed that religion played a role in
the war.
Theory 5: A border dispute. Following the War for Texas Independence (1836), Texans
claimed the Rio Grande River as the southeastern border of Texas, while Mexico
claimed its northeastern boundary was the Nueces
River.
Theory 6: Annexation of Texas. When the United States annexed Texas, U.S. leaders knew it
would provoke war with Mexico. Mexico had anticipated this might occur and
forewarned the United States. Regardless, the annexation of Texas
continued.