Hollins entered the navy of the United States as a midshipman in 1814 and served on the USS Erie in her attempt to break the British blockade of Chesapeake Bay.

Subsequently, he was on duty upon the ships Guerriere, Columbus, Franklin, and Washington, and commanded an East India merchantman for a time.

[3][4] In 1853, he led the Bombardment of Greytown (Nicaragua), a naval action initiated by the United States sloop-of-war USS Cyane, which he commanded.

Hollins then commanded the defenses afloat the Mississippi River, with his flagship the CSS Manassas on the coast of Louisiana.

Appointed flag officer in December 1861, he took a fleet up the Mississippi River to assist in the defense of the works at Columbus, Kentucky.