Construction of SSBN 6 was authorized by the President on 23 December 1958. On 27 June 1959, the President authorized construction of SSBNs 7, 8, and 9.On 1 July 1959, the FBM Program had, as its objective, a complete POLARIS/SSBN system with a 1200 nm range in 1960. Nine submarines and a submarine tender were authorized. On 15 July 1960, the President authorized construction of SSBNs 10, 11, 12, 13, and 14, and SSBNs 15, 16, 17, 18, and 19 were authorized by President John F. Kennedy on 29 January 1961. On 19 July 1961, the President authorized construction of SSBNs 20 through 29. The President signed the FY 63 Appropriations Act on 10 August 1962, providing funds for SSBN 30 through 35 and long-lead items 36 through 41. A total of 41 SSBNs were authorized by 2 July 1964, with the entire force to be operational in 1967.
The USS Proteus (AS-19), a submarine tender in mothballs at the Naval Shipyard, Charleston, South Carolina, was activated and converted into the first POLARIS FBM submarine tender, commissioned on 8 July 1960. By 1 July 1960, a second submarine tender had been authorized by the President. The third SSBN tender was authorized by President John F. Kennedy on 29 January 1961. The President signed the FY 63 Appropriations Act on 10 August 1962, providing funds for a fourth submarine tender.
All 41 SSBNs had been deployed by 3 October 1967. The first five SSBNs, USS George Washington class (SSBN-598), were deployed with POLARIS A1's. The next five SSBNs, USS Ethan Allen class (SSBN-608) were deployed with POLARIS A2's. Also, the next 9 boats of the USS Lafayette class (SSBN 616-626) were also deployed with POLARIS A2's. Plans called for the last 31 of the 41 SSBNs to all eventually carry POSEIDON C3 missiles.
The 10 George Washington and Ethan Allen class SSBNs were to off-load their A1's and A2's and eventually have POLARIS A3 missiles deployed in the Pacific. They operated out of Guam, serviced by the tender USS Proteus (AS-19) and, after 1967, by the tender USS Hunley (AS-31).
The POSEIDON C3 missiles would all be deployed in the Atlantic operating from tenders at Holy Loch, Scotland; Rota, Spain; and the new anchorage site established at Charleston, South Carolina. It was on 28 July 1965 that the USS Simon Lake (AS-33) officially became the support tender for Submarine Squadron Eighteen at an interim FBM anchorage at the U.S. Naval Station at Charleston, South Carolina. The anchorage was moved on 22 October 1965 to a permanent site on the Cooper River, Charleston, South Carolina.