From the information available on an enlistment record available through the US National Archives and Records Administration AAD website, William C. Zimmerman enlisted in the Air Corps as a private on October 9, 1941. His residence was in Blair County, Pennsylvania and he had been born in 1919. He had completed four years of high school, listed forman as an occupation, and was single without dependents.
During World War 2, he was assigned as a pilot with the 500th Bomb Squadron of the 345th Bomb Group flying the strafer version of the B-25 medium bomber. His Record of Combat Experience credits him with forty-five combat missions and the mission reports of the 500th Bomb Squadron place him on one additional mission. Both sources of missions flown were used to produce the map above.
My thanks to Kelly McNichols for supplying the Record of Combat Experience and to Clint Roby for allowing me access to his load list data.