Battles of the Mexican–American War

7 July 1846 · Monterey, Alta California

American victory; Monterey taken without a fight

Commodore John Sloat, who had been waiting off Mazatlán for news of war, sailed north to California, worried that Britain might get there first. At Monterey, the capital of Alta California, he landed about 250 sailors and marines, who raised the American flag over the customs house without a shot being fired, and declared California part of the United States.

7 August and 15 October 1846 · Mouth of the Papaloapan river, Alvarado

Mexican victories; both attacks called off

Commodore Conner twice tried to take the river port of Alvarado, south of Veracruz, where Mexican gunboats had taken shelter. Both times the strong current at the river bar and the fire of the forts stopped him; in October one of the schooners grounded and Conner called the attack off. Alvarado surrendered without a fight to a single American steamer the following spring.

24–26 October 1846 · Frontera and San Juan Bautista (Villahermosa), Grijalva river

American raid; the town was not held

Commodore Perry took the steamer Vixen, towing schooner gunboats, over the bar of the Grijalva river. He seized the port of Frontera with the ships in it, and then steamed more than 70 miles upriver to San Juan Bautista, the capital of Tabasco. His ships shelled the town after its governor refused to surrender, but Perry had too few men to hold it and went back downriver with his prizes.

9–29 March 1847 · Veracruz and the castle of San Juan de Ulúa

American victory; Veracruz surrendered

On 9 March Conner's ships landed General Winfield Scott's army on Collado beach south of the city in specially built surfboats: more than 10,000 men came ashore in a single afternoon without losing a man. Perry took over the squadron on 21 March. The ships could not risk the guns of San Juan de Ulúa, but Josiah Tattnall's 'mosquito fleet' of small steamers and schooners ran in close to bombard it until Perry called them back, and sailors landed six heavy naval guns and manned a battery that breached the city wall. Veracruz surrendered on 27 March, and Scott began his march on Mexico City.

18 April 1847 · Tuxpan river

American victory; Tuxpan taken

Perry turned on Tuxpan, the last Gulf port in Mexican hands. The steamers towed a long column of boats with about 1,500 sailors and marines over the bar and up the river, the men landing to storm the forts on the banks one after another while the gunboats covered them. The town was taken the same day.

15–16 June 1847 · San Juan Bautista (Villahermosa), Grijalva river

American victory; San Juan Bautista occupied

Perry came back to the Grijalva with a larger force. Ambushed from the river banks on the way up, he landed more than 1,100 sailors and marines with field guns and marched them on the town while the steamers fought past the obstructions in the river. The defenders fell back and San Juan Bautista was occupied, but disease soon forced the Americans out again.

20 October 1847 · Guaymas, Gulf of California

American victory; Guaymas taken

With California secured, the Pacific Squadron turned on the ports of western Mexico. Congress and Portsmouth bombarded Guaymas, the main port on the Gulf of California, and landed parties that occupied the town after its garrison withdrew inland.

11 November 1847 · Mazatlán, Sinaloa

American victory; Mazatlán occupied

Commodore Shubrick brought Independence, Congress and Cyane into Mazatlán, Mexico's biggest Pacific port, and landed about 700 sailors and marines. The Mexican garrison withdrew without a fight, and the port stayed in American hands until the end of the war.