The largest group of reinforcements arrived
after the fall of Bataan. In the days following 9 April, 72 officers
and 1,173 enlisted men from more than 50 different organizations
were assigned to the 4th Marines, making the Marine regiment one of
the most unusual units in Marine Corps history. These reinforcements
included members of the Navy, the Army, the Philippine Army and
Philippine Scouts. Sailors stranded on land after the loss of their
ships found themselves alongside engineers, tankers, and aviators
whose units were captured on Bataan. Filipino Scouts were assigned
with members of the islands' Constabulary to the 4th Marines.
Unfortunately, very few of the reinforcements were trained or
equipped for ground combat. By 29 April, the 4th Marines numbered
229 officers and 3,770 men, of whom only about 1,500 were Marines.