He attended Santa Cruz High School, graduating in 1928,[1] and then enrolled at University of San Francisco.
Reporting on the war he covered the Allied invasion of North Africa in 1942, also served in Greece, the Balkans, and Austria.
In 1945, freshly returned from the combat zones in Europe and Africa, Gallagher was appointed to head AP operations in Germany.
He outscooped his rivals on the verdicts by dashing 100 yards to where his wife, Betty, waited with an open phoneline.
He led the Nuremberg coverage for the AP along with Pulitzer Prize winners Dan DeLuce and Louis P. Lochner.