At the end of the Nineteenth Century, the World's navies, like its heavy industries, ran on coal. The U.S. Navy of the time relied on coal piles at its bases to keep its ships going. Deployed units, like Dewey's Asiatic Squadron, got their coal from local vendors. With the coming of war, these fuel sources would either be too far from likely areas of operations or denied to combatant forces by neutrality laws. In March and April 1898, the Navy urgently looked for available colliers, as coal transport ships were called, and was able to purchase twenty.

These ships were mainly of British construction, reflecting the contemporary character of both shipbuilding and the coal trade. Most were used to replenish the bunkers of Sampson's and Schley's ships in the Caribbean area, where one, USS Merrimac, was expended in a heroic effort to bottle up the Spanish fleet at Santiago, Cuba. Dewey had one newly-obtained collier, USS Nanshan, to support his ships in Manila Bay. Two others, Brutus and Nero, escorted the monitors Monterey and Monadnock from California to the Far East.

The Spanish-American War colliers generally had long Navy careers, reflecting post-war requirements for a flexibly-located and abundant coal supply. As warships gradually converted to oil fuel in the World War I era, many colliers found other employment as general cargo ships, surveying ships and target tenders. The survivors passed out of service during the 1920s.