In December 1843, Voorhees joined Commodore Daniel Turner's Brazil Squadron blockading Montevideo in safeguarding U.S. trade during the Uruguayan Civil War.

Large detachments of her crew participated in battles on Rio San Gabriel and the plains of La Mesa, and in the occupation of Los Angeles.

On August 23, 1848, she departed La Paz, Baja California Sur for Norfolk, Virginia, arriving the following January to be placed in ordinary.

In 1859, Congress was reassigned as flagship of Commodore Joshua R. Sands and the Brazil Squadron, remaining in that area until the Civil War precipitated her return to Boston, Massachusetts on August 22, 1861.

The ironclad and her consorts attacked from a distance and inflicted great damage on the ship, killing 120, including the commanding officer, Joseph B. Smith.

Ablaze in several places and unable to bring guns to bear on the enemy, Congress was forced to strike her colors and raise a white flag.

[3] Instead she fired several rounds of hot shot (red-hot cannonballs) and incendiary causing Congress to burn to the water's edge, and her magazine to explode.