The spark of the Mexican-American War was when...

Question 4 options:

General Taylor attacked Mexico City

General Scott's troops fired the first shots

General Kearny attacked Santa Fe

General Taylor's troops crossed into "Mexican Territory"

*Please answer before 6:30 PM tonight. *

General Taylor's troops crossed into the "Mexican Territory."

Explanation:

The spark of the "Mexican-American" war happened when General Taylor's troops crossed into the "Mexican Territory." This happened when President Polk tried to re-establish diplomatic relations with Mexico because the country broke relations in early 1845.

Despite the U.S. government's effort, the Mexican government refused to communicate. General Taylor then sent his troops across the Rio Grande so they could communicate with the Mexican officials. The crossing of the troops at the Mexican territory was deemed an act of war for the Mexicans, since it was an invasion of their territory. This started the Mexican-American war and it kicked off. This then resulted to the Mexicans crossing the border and attacking some American soldiers.

So, this explains the answer.