The 6"/50 caliber gun Mark 6 and Mark 8 were used for the secondary batteries of the United States Navy's Maine-class and Virginia-class battleships, as well as the Pennsylvania-class and Tennessee-class armored cruisers. They were also used as the main battery on the St. Louis-class protected cruisers.

The Tennessee-class cruisers were four armored cruisers built for the United States Navy between 1903 and 1906. Their main armament of four 10-inch (254 mm) guns in twin turrets was the heaviest carried by any American armored cruiser. Their armor was thinner than that of the six Pennsylvanias which immediately preceded them, a controversial but inevitable decision due to newly imposed congressional restraints on tonnage for armored cruisers and the need for them to be able to steam at 22 knots. However, the fact their armor covered a wider area of the ship than in the Pennsylvanias and their increased firepower caused them to be seen by the Navy as an improvement.