On 18 February 1961, "Theodore Roosevelt" departed Mare Island, California, bound for the United States East Coast. On 7 March, she became the first FBM submarine to transit the Panama Canal. On 11 March 1961, she arrived at Cape Canaveral, Florida. After successfully firing her first Polaris A1 missile on 20 March 1961 and completing her shakedown training, she arrived in Groton, Connecticut, on 1 May for post-shakedown repairs at the Electric Boat Company shipyard. She completed those repairs on 24 June 1961 and departed Groton, bound for Charleston, South Carolina. "Theodore Roosevelt" stopped at Norfolk, Virginia, along the way and arrived at Charleston on 7 July 1961. Between 7 July and 19 July 1961, she loaded Polaris missiles at the Naval Ammunition Depot, Charleston, and made all other preparations for her first deployment. On 19 July 1961, she stood out of Charleston on her first deterrent patrol. She concluded that patrol on 23 September 1961 at the FBM submarine base at Holy Loch, Scotland.