Following fitting out and tests at Galveston, Texas, and shakedown off Bermuda, "Leland E. Thomas" got underway for Massachusetts on 11 August, arriving at Boston on 13 August. After completing availability at the Boston Navy Yard, the destroyer escort headed for Norfolk, Virginia, arriving 25 August. Two days later she began hunter-killer operations along the U.S. East Coast until she headed for Maine 5 September, arriving at Casco Bay on 6 September. She operated along the Atlantic coast until she sailed for Italy on 20 September, escorting a convoy into Naples, Italy on 4 October.