The Defense Base Act (DBA) was enacted on August 16th, 1941, extending the federal workers' compensation program that protects longshoremen and harbor workers. The program, which is administered by the United States Department of Labor (DOL), was extended to provide medical care and award workers' compensation benefits to civilian employees of defense contractors injured during the scope of their work at overseas United States defense bases and other public works.
The extension covering employees of defense contractors was passed in December 1942 as the War Hazards Compensation Act (WHCA.) The WHCA recognizes that the citizens of the United States should bear the cost of war risk injuries and deaths.
The DOL administers the DBA through three Districts in the U.S., which are the Eastern, Southern, and Western Districts which have sub-offices in major U.S. cities. Here is more information to cover questions concerning, "What is the Defense Base Act?"