Inconclusive The Capture of Monterey by the United States Navy and Marine Corps occurred in 1842.

After hearing false news that war had broken out between the United States and Mexico, the commander of the United States Navy Pacific Squadron Thomas ap Catesby Jones sailed from Lima, Peru with three warships to Monterey, California, the capital of Alta California.

Commodore Jones sent his second-in-command, Captain James Armstrong, ashore to demand a Mexican surrender by 9:00 a.m. the following morning.

It was only the next day that Jones learned that war had not begun between the United States and Mexico and that the British were not preparing to take control of California.

The incident proved unpopular in Mexico, and in response, Monterey's garrison constructed shore batteries and other defenses to guard its city from future attack, which came in 1846, during the Mexican–American War.