California Battalion - Formation

Formation

Hostilities between U.S. and Mexican forces had been underway in Texas since April 1846 resulting in a formal declaration of war on 13 May 1846, by the U.S. Congress. On 17 May 1846, unofficial word reached the U.S. Navy fleet of four vessels at anchor in the harbor of Mazatlán, Mexico, that hostilities had begun between Mexico and the United States. CommodoreJohn D. Sloat, commander of the U.S. Navy's Pacific Squadron, dispatched his flagship, the frigate USS Savannah, and the Sloop USS Levant to Monterey harbor where they arrived on 2 July 1846. The U.S. Navy's Pacific Squadron captured Monterey, California on 7 July 1846 and began taking over the ports in Alta California. The Bear Flag Revolt was converted into a U.S. occupation of California and the Bear Flag was replace by the Stars and Stripes.

In 1846, U.S. Marine Lieutenant Archibald H. Gillespie was sent by President James K. Polk with secret verbal messages to the U.S. Consul Thomas O. Larkin in Alta California's Capital in Monterey, California, Commodore John D. Sloat commanding the Pacific Squadron and U.S. Army Captain John C. Frémont doing cartography work in California. Traveling secretly across Mexico, Lt. Gillespe caught a ship from Mexico to Monterey, California where he delivered his messages to Thomas Larkin and Sloat. Finding that Fremont was on his way to Oregon he borrowed a horse and hurried north where he caught up with Fremont's party near what is now the Oregon border. After delivering his messages, Gillespie and John C. Fremont with his about 30 U.S. Army Cartographers, etc. and 30 scouts and hunters turned around and headed back to California where he helped Fremont take over command of 14 June 1846 Bear Flag Revolt of California. When it became clear that the U.S. Navy was taking action to secure California the Bear Flag Revolt was converted into a U.S. military action.

Since there was no U.S. Army present in Alta California except Fremont's few cartographers (and wouldn't be till December 1846), Stockton needed additional men to garrison and help keep the peace in the various California towns rapidly coming into U.S. control. Stockton had three frigates with a crew of 480 each, three to four sloops with a crew of 200 men each plus three store ships at his disposal. The Marines on his ships were used mostly to board or repel boarders or engage in close in ship to ship fighting and were trained in infantry tactics. The U.S. Marines and some sailors could be reassigned shore duties and while leaving the ships short handed but still functional. He looked to employ his reassigned 300-400 marines and blue-jacket sailors only where needed.