1). April 25, 1846: The Mexican-American War begins when Mexican troops cross north of the Rio Grande River and opened fire on U.S. troops at Fort Texas.
2). May 8, 1846: Battle of Palo Alto- The first official battle of the war. After Mexican troops retreat, Taylor declares his army victorious.
3). May 9, 1846: Battle at Resaca de la Palma- The day after the Battle at Palo Alto, Taylor’s troops follow Mexico’s retreating men to Resaca de la Palma (resaca is the Spanish term for a dry riverbed) and were victorious again.(8)
4). May 13, 1846: Congress officially declares war on Mexico.
5). Summer, 1846: Thousands of American volunteers were authorized by Congress for twelve-month military service and arrived in the lower Rio Grande Valley shortly thereafter. “Most Americans enthusiastically supported the war. Approximately 75,000 men eagerly enlisted in volunteer regiments raised by the various states. Thousands more enlisted in the regular U.S. Army. There was no need for a draft. In some places, so many men flocked to recruiting stations that large numbers had to be turned away.”
6). June, 1846: American settlers in California arrest Mexican politician Mariano Guadalupe Vallejo, part of what is referred to as the "Bear Flag" revolt. The Americans write a constitution and declare California an independent republic.
7). July 7, 1846: Battle of Monterey- General Taylor’s army followed the Mexican troops to Monterey and fought to take control of this city. “The fighting was fierce. In the end, it came down to hand-to-hand combat in the city streets. But again, the American army was victorious.”(10)
8). August 14, 1846: U.S. Colonel Stephen Watts Kearney, whose first mission was to occupy New Mexico, rode with troops into its capital, Sante Fé, and finding it deserted, easily took possession.(11)
9). August-September 1846: Many U.S. volunteers assemble under General John E. Wool, who lead them to go join General Taylor