Commodore Stockton soon mounted his men and prepared for operations on shore. Skirmishes followed, and were continually occurring until January, 1847, when a decisive action occurred. General Kearny had arrived in California, after a long and painful march overland, and his co-operation was of great service to Stockton. The Americans left San Diego on the 29th of December, to march to Los Angeles. The Californians determined to meet them on their route, and decide the fate of the country in a general battle. The American force amounted to six hundred men, and was composed of detachments from the ships Congress, Savannah, Portsmouth and Cyane, aided by General Kearny, with sixty men on foot, from the first regiment of United States dragoons, and Captain Gillespie with sixty mounted riflemen. The troops marched one hundred and ten miles in ten days, and, on the 8th of January, they found the Californians in a strong position on the high bank of the San Gabriel river, with six hundred mounted men and four pieces of artillery, prepared to dispute the passage of the river. The Americans waded through the water, dragging their guns with them, exposed to a galling fire from the enemy, without returning a shot. When they reached the opposite shore, the Californians charged upon them, but were driven back. They then charged up the bank and succeeded in driving the Californians from their post. Stockton, with his force, continued his march, and the next day, in crossing the plains of Mesa, the enemy made another attempt to save their capital. They were concealed with their artillery in a ravine, until the Americans came within gun-shot, when they opened a brisk fire upon their right flank, and at the same time charged both their front and rear. But the guns of the Californians were soon silenced, and the charge repelled. The Californians then fled, and the next morning the Americans entered Los Angeles without opposition. The loss of the Americans in killed and wounded did not exceed twenty, while that of their opponents reached between seventy and eighty.
These two battles decided the contest in California. General Flores, governor and commandant-general of the Californians, as he styled himself, immediately after the Americans entered Los Angeles, made his escape and his troops dispersed. The territory became again tranquil, and the civil government was soon in operation again in the places where it had been interrupted by the revolt. Commodore Stockton and General Kearny having a misunderstanding about their respective powers, Colonel Fremont exercised the duties of governor and commander-in-chief of California, declining to obey the orders of General Kearny.