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 three Maine-class battleships—Maine, Missouri, and Ohio—were built at the turn of the 20th century for the United States Navy. Based on the preceding Illinois class, they incorporated several significant technological advances over the earlier ships. They were the first American battleships to incorporate Krupp cemented armor, which was stronger than Harvey armor, smokeless powder, which allowed for higher-velocity guns and water-tube boilers, which were more efficient and lighter. The Maines were armed with four 12-inch (305 mm) guns and sixteen 6-inch (152 mm) guns, and they could steam at a speed of 18 knots, a significant increase over the Illinois class.