The Sturgeon class (known colloquially in naval circles as the 637 class) was a class of nuclear-powered fast attack submarines (SSN) in service with the United States Navy from the 1960s until 2004. They were the "workhorses" of the Navy's attack submarine fleet throughout much of the Cold War. The boats were phased out in the 1990s and early 21st century, as their successors, the Los Angeles, followed by the Seawolf and Virginia-class boats, entered service.
(More on Wiki HERE)