Following shakedown, she operated off the east coast escorting convoys and aircraft carriers. These convoy missions took "Macomb" south to the northern coast of South America, east to the West African coast, and north to Newfoundland. Standing out of Boston on 5 July 1942, "Macomb" escorted a U.S. Army transport and an English ship to Greenock, Scotland, arriving 12 July. She operated between Scotland and Iceland making one round-trip voyage to New York for availability, until 25 September 1942, when she anchored at Norfolk, Virginia Departing Norfolk on 11 October, she screened aircraft carrier anti-submarine patrols in the Caribbean until heading for the north African coast 7 November. Arriving on the 11th, she acted as carrier screen during the landings at Casablanca and returned to Boston after the landings were secure.