Though sometimes outnumbered by the Royal Navy, the United States fleet deployed out of Bellingham and Port Townsend was prepared to fight, if necessary.
The first of the U.S. ships was the U.S.S. Active, a side-wheel steamer originally built as the Gold Hunter in 1849. The Active would take part in the North West Boundary Commission survey of the San Juan Islands. When the Pig War kicked off, the Active and her crew abandoned a hydrographic mission to participate in the dispute.
The second American ship to take part was the U.S.R.C. Jefferson Davis, named after the then Secretary of War and later the President of the Confederate States of America. Built in Rhode Island in 1853, the Jefferson Davis was a 177-ton topsail schooner. The ship arrived on the West Coast in 1854, the first United States Revenue Cutter Service ship stationed north of San Francisco. The ship participated in the Puget Sound War against local Native tribes and would remain in the Puget sound unit she was sold in 1862.
The third ship that the U.S. deployed was be the U.S.S. Massachusetts, built in 1845 as a propeller-driven steam ship that was also equipped with sails. The Massachusetts served to transport troops to the Mexican War and later took part in an expedition to the Kingdom of Hawaii. As tensions rose with England, the ship's guns were removed and used to strengthen the redoubt at American Camp. After the Pig War, the Massachusetts was transferred back to the Army to protect the settlers of the region.
The final U.S. ship to take part of the Pig War was the Shubrick. Built in 1857, she was a single-engine steamer also rigged up as a brigantine. In Puget Sound she was used as a lighthouse tender and revenue cutter. During the Civil War, the Shubrick was transferred to the Revenue Cutter Service and was later sent to the Bering Strait to help and support a survey operation conducted by the Russian Telegraph Company.