Willow Run, aka Air Force Plant 31, was located near Ypsilanti, Michigan.
By November 1943 they were rolling out a new B-24 every hour. At its peak monthly production (August 1944), Willow Run produced 428 B-24s with highest production listed as 100 completed Bombers flying away from Willow Run between April 24 and April 26, 1944. By 1945, Ford produced 70% of the B-24s in two 9-hour shifts. Ford built 6,972 of the 18,482 total B-24s and produced kits for 1,893 more to be assembled by the other manufacturers. The B-24 holds the distinction of being the most produced heavy bomber in history. One of the many reasons the USA manufacturing prowess won the war.