Ethan Allen's keel was laid down by the Electric Boat Corporation of Groton, Connecticut. She was launched on 22 November 1960, sponsored by Mrs. Robert H. Hopkins, great-great-great-granddaughter of Ethan Allen. The ship was commissioned on 8 August 1961, with Captain Paul L. Lacy, Jr., commanding Blue Crew and Commander W. W. Behrens, Jr., commanding the Gold Crew
Ethan Allen (Navy hull design SCB-180) was the first submarine designed as a ballistic missile launch platform.[5] (The earlier George Washingtons were converted attack submarines.) She was constructed from HY80 steel (high yield, 80,000 psi (550,000 kPa) yield strength),[6] and was fitted with the Mark 2 Mod 3 Ships Inertial Navigation System (SINS).[7] At launch, she was outfitted with Polaris A-2 (UGM-27B) submarine launched ballistic missiles (SLBMs) and Mark 16 Mod 6 torpedoes; the torpedo firecontrol system was the Mark 112 Mod 2.[8] The A-2s would be retrofitted with Polaris A-3s and their gas/steam ejection launch gear and Mark 80 firecontrol systems during 1965,[9] while in the 1970s these would be replaced with A-3Ts.[10] In addition, Allen was updated with Mark 37 and (later) Mark 48 torpedoes during her operational lifetime
On 6 May 1962, Ethan Allen, under Captain Lacy and with Admiral Levering Smith aboard, launched a nuclear-armed Polaris missile that detonated at 11,000 feet (3.4 km) over the South Pacific. That test (Frigate Bird), part of Operation Dominic I, was the only complete operational test of an American strategic missile. The warhead hit "right in the pickle barrel."