The Mexican American War
The Pacific Squadron, also known as the Pacific Station, was part of the United States Navy squadron stationed in the Pacific Ocean in the 1800s and early 1900s. Initially with no U.S. ports in the Pacific they operated out of storeships which provided naval supplies and purchased food (when available) and obtained water from local ports of call in Hawaii and the West Coast. Over one-half the U.S. Navy would be sent to join the Pacific Squadron during the Mexican American War.

History
Established in 1821, this small force confined its activities initially to the Pacific waters off South America, North America and Hawaii protecting United States commercial shipping interests. It expanded its scope of operations to include the Western Pacific in 1835, when the East India Squadron joined the force. The squadron was reinforced when war with Mexico began to seem a possibility. Sailing from the east coast to the west coast around Cape Horn was a 13,000 miles (21,000 km) to 15,000 miles (24,000 km) journey that typically took from 130 to 210 days.

The Pacific Squadron was instrumental in the capture of California in the Mexican American War of 1846-1848 after war was declared on 24 April 1846. The Navy was essentially the only significant U.S. military force on the Pacific coast in the early months of the Mexican American War. They had orders, in the event of war, to seize the ports in California. There was a small exploratory force of Lieutenant Colonel John C. Fremont's 60 man exploratory expedition (about half were Army soldiers the rest Indians and ex-mountain men) in the U. S. Corps of Topographical Engineers. Fremont joined forces (apparently with 'secret orders' to assist in any revolution in California) with a volunteer force of California residents who formed the California Battalion to help garrison the towns rapidly captured from the Californio government. The California Battalion varied in size with time from about 160 initially to over 400. Under John D. Sloat, Commodore of the Pacific Squadron, the USS Savannah (Frigate, 44 guns, crew 480) USS Cyane, and USS Levant (both were Cyane class sloops with: 22 guns, crews of about 200, 132 feet long, 792 tons) captured the California capital of Monterey California without firing a shot 7 July 1846. USS Portsmouth (sloop 20 guns, crew of 210) captured San Francisco 9 July 1846 without firing a shot. Shortly thereafter the short lived Bear Flag Rebellion was converted into a U.S. military conflict for possession of California. The Frigate USS Congress (44 guns crew 480, 1,867 tons 197 feet long) was the flagship of Commodore Robert F. Stockton when he took over as the senior U.S. military Commander in California in late July 1846. The USS Congress is credited with capturing San Pedro, California 6 August 1846 and helping capture Mazatlan, Mexico 44 November 1847. The ships (and their accompanying storehouse ships) served as floating store houses keeping Fremont's volunteer force of about 300-400 men in the California Battalion supplied with powder, lead and supplies as well as transporting them to different California ports. The USS Cyane transported Fremont and about 160 of his men to San Diego, California which was captured 29 July 1846 without a shot being fired. Commodore Robert Stockton appointed Fremont as military governor of California. In addition Commodore Stockton used about 400-500 marines and bluejacket sailors from his squadron to supplement the approximate 90 men supplied by Brigadier General Stephen W. Kearny and Fremont's volunteer California Battalion of about 400 men to re-take Los Angeles and convince the Californios to sign on 13 January 1847 the Treaty of Cahuenga, terminating the war in upper California.

The retired Ship of the line USS Independence (1814) was brought back into service, cut down and recommissioned as a razee Frigate. The newly reconfigured ship removed the old top deck and reduced the gun count from 90 to 54 making her much easier to sail. The rebuilt USS Independence (1814), now classified as a 'heavy' Frigate, launched on 4 August 1846 when the nation was already at war with Mexico and departed Boston 29 August 1846 for California. She entered Monterey Bay on 22 January 1847 and became the flagship of Commodore William Shubrick, now commanding the Pacific Squadron.

In July of 1846, Colonel Jonathan D Stevenson of New York was asked to raise a volunteer regiment of ten companies of 77 men each or 770 men to go to California with the understanding that they would be muster out and stay in California. They were designated the 1st New York Volunteers. In August and September the regiment trained and prepared for the trip to California. Three private merchant ships, Thomas H Perkins, Loo Choo, and Susan Drew, were chartered, and the Sloop USS Preble was assigned convoy detail. On September 26, the four ships sailed for California. Fifty men who had been left behind for various reasons sailed on 13 November 1846 on the small Storeship Brutus. The Susan Drew and Loo Choo reached Valparaiso, Chile by 20 January 1847 and they were on their way again by 23 January. The Perkins did not stop until San Francisco, reaching port on 6 March 1847. The Susan Drew arrived on 20 March and the Loo Choo arrived on 26 March 1847, six months (183 days) after leaving New York. The Brutus finally arrived on 17 April 1847. Counting desertions and deaths the three ships brought 599 men plus 49 more on the Brutus to California. The companies were then deployed throughout Upper and Lower California from San Francisco to La Paz, Mexico. The ship Isabella sailed from Philadelphia on 16 August 1847, with a detachment of one hundred soldiers, and arrived in California on February 18th, 1848; at about the same time that the ship Sweden arrived with another detachment of soldiers. These troops essentially replaced all Pacific Squadron's on shore military and garrison duties.

USS Independence assisted in the blockade of the Mexican Pacific coast, capturing the Mexican ship Correo and a launch on 16 May 1847. She supported the capture of Guaymas Mexico on 19 October 1847 and landed bluejackets and Marines to occupy Mazatlán, Mexico on 11 November 1847. She later cruised as far as Hawaii, arriving Honolulu on 12 August 1848. Independence returned to the East Coast Naval base at Norfolk, Virginia on 23 May 1849 and was decommissioned there on 30 May 1849.

After upper California was secure most of the squadron proceeded down the California coast capturing all major Baja California cities and capturing or destroying nearly all Mexican vessels in the Gulf of Mexico. Baja was given back to the Mexicans when a dispatch rider was captured with dispatches that gave instructions to the United States negotiators in Mexico City that Baja was 'negotiable'--the Mexican negotiators promptly 'negotiated' it back. Numerous Mexican ships were also captured by this squadron with the USS Cyane given credit for 18 captures and numerous destroyed ships. Entering the Gulf of California, Independence, Congress and Cyane seized La Paz captured and/or burned the small Mexican fleet at Guaymas. Within a month, they cleared the Gulf of hostile ships, destroying or capturing 30 vessels. Independence Congress, and Cyane and their bluejackets and Marines captured the town of Mazatlan, Mexico, 11 November 1847. USS Cyane returned to Norfolk 9 October 1848 to receive the congratulations of the Secretary of the Navy for her significant contributions to American victorys in Mexico and California. The Treaty of Guadalupe Hidalgo, signed in February 1848, marked the end of the Mexican-American War.

This is about the end of the U.S. Sailing Navy's use of sailing ships as armored steamships were rapidly introduced in the American Civil War.

The extent of the Pacific Squadron's responsibility was further enlarged in the 1850's when California and Oregon were admitted to the country and Navy bases on the west coast were established.

In 1903, the squadron consisted of armored cruiser New York, cruisers Boston and Marblehead and the gunboat Ranger.

In early 1907, the Pacific Fleet was formed. The Asiatic Squadron became the First Squadron and the Pacific Squadron became the Second Squadron.