The age of battleships is long over. The United States built the USS Missouri, the nation's last battleship, in 1944, even as that category of "heavy ship with many powerful guns" was superseded by "floating runway with many powerful planes." Though aircraft carriers would eventually replace battleships, both were used during WWII. Readers on the home front were curious about how these behemoths worked, and in October 1943, Popular Science obliged with the above infographic of the North Carolina class of battleships.
The North Carolina class was primarily armed with three turrets, each containing three guns 16 inches in diameter. These guns could fire two explosive or armor-piercing rounds a minute, at enemies up to 22 miles away. That's an impressive distance for a single gun, but still not enough to match the increasing advantage of airplanes: the F4U Corsair, a standard Naval fighter used on aircraft carriers during the era, could fly more than 1,000 miles while carrying bombs. Despite many mighty guns, the battleship's limited power in the new age of carrier warfare relegated it to a support role. Large crew sizes—the North Carolina class regularly traveled with 2,339 people on board—were another reason for the battleship's eventual retirement.
Bonus! Here's a U.S. Navy training video from 1955. It took 79 men to load and operate a battleship gun turret: