Western Port – a former merchant steamer built at Philadelphia, in 1853 – was chartered by the United States Department of the Navy in the autumn of 1858 to participate in an American naval expedition up the Paraná River to Asunción, Paraguay.

Western Port soon sailed for South American waters and – at Montevideo, Uruguay, – joined the task force commanded by Flag Officer William Branford Shubrick, which had been assembled to support the negotiations of United States Commissioner to Paraguay, James Butler Bowlin.

President of the United States James Buchanan had appointed Bowlin to seek redress for the shelling of the U.S. Navy sidewheel gunboat USS Water Witch in 1855, which had resulted in the death of the American ship's helmsman.

She arrived off Asunción on 25 January 1859, and Bowlin went ashore to conduct negotiations which succeeded in winning an apology to the United States and a large indemnity for survivors of the dead helmsman.

These actions saved Key West for the Union, permitting its wartime use as the home port of the U.S. Navy's Gulf Blockading Squadron.

On detail, Wyandotte salvaged valuable supplies from the schooner Marie Banks, wrecked off Cape Henry Light, Virginia, on 10 February 1863.

She was redocumented for merchant service on 23 September 1865, but was stranded when she ran aground off Duxbury, Massachusetts, on 26 January 1866 and was damaged beyond economical repair.