[2] Callao spent her Spanish Navy career on colonial duties in the Philippine Islands.

Her crew was unaware that war had been declared or that the Spanish Navy squadron of Rear Admiral Patricio Montojo y Pasaron had been destroyed by the U.S. Navy's Asiatic Squadron under Commodore George Dewey in the Battle of Manila Bay eleven days earlier when, on 12 May 1898, Callao steamed into Manila Bay en route the harbor.

[2] When Dewey's ships sighted the inbound gunboat, cruiser USS Raleigh got underway to investigate.

They were quickly paroled ashore at Cavite, and it was later rumored that the commanding officer of Callao was sentenced to death by Spanish authorities for not fighting back against the American ships.

This article incorporates text from the public domain Dictionary of American Naval Fighting Ships.