The 602nd Bombardment Squadron (Heavy) was constituted on 15 February 1943, activated on 1 March 1943, and inactivated on 1 September 1945. It was assigned to the 398th Bombardment Group.
The squadron was based at Ephrata Army Air Base, in Washington State, when in early April 1943 it was rotated via Blythe Army Air Field, in California; Geiger Field, Washington; Rapid City Army Air Base, South Dakota, ending up in Nuthampstead, England from April 1944 to May 1945.
The 602nd flew the Boeing B-17 Fortress in combat in the European Theater of Operations, contributing its efforts in the Air Offensive, Europe; Normandy; Northern France; Rheinland; Ardennes-Alsace, and Central Europe.
On 3 July 1945 the squadron was rotated to Drew Field, Florida where it was inactivated on 1 September 1945. This squadron patch was officially approved on 6 March 1944