What was the name of the first nuclear-powered submarine, launched in 1954?

The first nuclear-powered submarine, launched in 1954, was USS Nautilus (SSN-571).

The United States Navy’s Nautilus was authorized in 1951 and built by General Dynamics’ Electric Boat division in Groton, Connecticut. Its keel was laid on June 14, 1952, and it was launched on January 21, 1954, with First Lady Mamie Eisenhower as sponsor. The submarine was commissioned on September 30, 1954, under Commander Eugene P. Wilkinson.

Nautilus used a pressurized-water reactor, designated the S2W, developed through the Navy’s nuclear-propulsion program led by Captain Hyman G. Rickover. Nuclear power let the submarine remain submerged far longer than diesel-electric boats because it did not need atmospheric oxygen for propulsion. In 1955, Nautilus famously transmitted the message “Underway on nuclear power.” It later became the first submarine to complete a submerged transit of the North Pole, in 1958. USS Skate, Seawolf and Triton were later nuclear submarines, not the first.