During the period when battleships were the pride of the navy and the countries that produced them, the major sea powers were constructing ever larger and more sophisticated dreadnoughts to keep pace with the rest of the world. In 1921 the three major naval powers, (U.S.A., Great Britain, Japan) met in an attempt to limit the size and number of capital ships of each navy in hopes of maintaining world peace following world war 1. The agreement was eventually signed, and remained in effect until 1934, when Japan withdrew from the pact and from the beginning of 1937 all major powers resumed construction of new capital ships. The dark clouds gathering on the horizon that threatened world peace during the late 1930's started the U.S. Navy on a robust construction program. Two North Carolina class battleships (BB-55 and 56), which mounted nine 16 inch guns and with a displacement of 35,000 tons, were started in 1937. In 1938 four South Dakota class battleships (BB-57-60) which had the same main guns and displacement but better defensive armament, were laid down. All six of these battleships were commissioned during 1941-42 and greatly strengthened the U.S. fleet.

On the drawing boards at the time these ships were commissioned were six new Iowa class battleships of 45,000 tons each. Only four (BB-61 Iowa, BB-62 New Jersey, BB-63 Missouri and BB-64 Wisconsin) were completed and took part in the 2nd world war. Five additional Montana class battleships were planned, at 60,500 tons, but were cancelled prior to construction. The Iowa class battleships were design masterpieces for the U.S.A. Defensive armament was stressed and to allow passage through the Panama Canal, the same 32.95 meter beam of the North Carolina ships was adhered to. With a 10,000 ton increase in displacement over the North Carolina class ships, the Missouri was 48 metes longer, giving the Iowa class ships the graceful clipper bow, flat deck and tower type superstructure. Although the narrow beam and increased length made for greater speed, the roll rate during heavy seas was considered severe, making side defensive armament less effective.

The new Mk7 16 inch bore 40 caliber rifles on the Missouri were much more powerful than those 16 inchers on the North Carolina, and when completed the BB-63 had ten twin 5" turrets for anti-aircraft defense and small targets aground or afloat; 20 quadruple 40mm Bofors anti-aircraft guns and 49 single 20mm AA guns. In addition the Missouri carried four float planes which were launched from the steam catapults located on the stern. Power to move this big ship came from eight boilers, oil fired, arranged in four fire rooms, and with each turbine located in a separate room From forward to aft, the arrangement was fire room, engine room, repeated four times. With a total of 212,000 shaft horsepower available, the Missouri had a flank speed of 33 knots and a cruising radius of 15,900 n.m. at 17 knots. Even though the USS Missouri had a displacement of 17,000 tons less than the largest battleship ever floated, the Japanese Yamato, it was 18.9 meters longer, 62,000 hp more powerful, 6 knots faster and had twice the cruising radius. Its defensive armament was much stronger than the Yamato, but the destructive power of the Missouri's main 16" guns could not match that of the Yamato's 18 inch weapons. The BB-63 Missouri was commissioned on 6 November 1944, fitted for sea duty and dispatched to the Pacific area, where she arrived in January 1945. She served in this area as support for the carrier task forces then engaged in the Iwo Jima, Okinawa and bombardment of the Japanese mainland campaigns. On 2 September 1945 the surrender ceremonies were completed on the deck of the Missouri while anchored in Tokyo bay.

The Missouri departed the area for New York on 6 September where she served in a training capacity for the navy. The other three Iowa Class battleships were put into storage and decommissioned. When the Korean conflict erupted in 1950, the Missouri was sent to that area for shore bombardment duties and acted as the flag ship of the U.S. 7th fleet. When that conflict was terminated the Missouri served again in a training capacity and was decommissioned in 1955. At the time of this writing (1985) the Mighty Mo is again being reconfigured and will soon join her sister ships the BB-61 Iowa and BB-62 New Jersey, patrolling the seas of the world to assist in keeping the peace.