The Des Moines-class cruisers were a trio of very large U.S. Navy heavy cruisers commissioned in 1948 and 1949. Largely based on the earlier Baltimore-class heavy cruisers, the Des Moines-class featured improved torpedo protection and heavier anti-aircraft armament. Relatively well-armored and protected, the class was unique in that it mounted nine of the world’s first auto-loading large-claiber guns, the 8-inch (203 mm) Mark 16 guns. These guns enabled the Des Moines to fire two to three times faster than earlier 8 in guns with each barrel capable of 8-10 rounds per minute. They were the last of the “all-gun” heavy cruisers and were exceeded in size within the U.S. Navy only by the 30,000-long-ton (30,481 t) Alaska-class “large cruisers” that straddled the line between heavy cruisers and battlecruisers. Two were decommissioned by 1961 but the Newport News (CA-148), served until 1975. USS Salem is a museum ship in Quincy, Massachusetts; the other two were scrapped.

A heavy cruiser was a type of cruiser, a naval warship designed for long range and high speed, armed generally with naval guns of roughly 203 mm (8 inches) in calibre, whose design parameters were dictated by the Washington Naval Treaty of 1922 and the London Naval Treaty of 1930. Heavy cruisers were generally larger, more heavily-armed and more heavily-armoured than light cruisers while being smaller, faster, and more lightly-armed and armoured than battlecruisers and battleships. Heavy cruisers were assigned a variety of roles ranging from commerce raiding to serving as 'cruiser-killers,' i.e. hunting and destroying similarly-sized ships