A two thousand-man Mexican cavalry detachment crosses…
April 1846 CE
This sparks the "Thornton Affair", an ambush that takes place twenty miles west upriver from Zachary Taylor's camp along the Rio Grande.
The Mexican cavalry routs the patrol, killing eleven American soldiers.
Regarding the beginning of the war, Ulysses S. Grant, who opposes the war serves as an army lieutenant in Taylor's Army, claims in his Personal Memoirs (1885) that the main goal of the U.S. Army's advance from Nueces River to Rio Grande was to provoke the outbreak of war without attacking first, to debilitate any political opposition to the war.