World War I recruits were screened for tuberculosis almost exclusively with a history and physical exam. Radiography was unavailable on a large scale and expensive. New techniques developed in Brazil and elsewhere in the 1930s made mass radiographic screening practical. During World War II, the U.S. Army and Navy took advantage of this new technology to screen an estimated 10 million personnel. This ambitious and successful case-finding program inspired, in part, continuing radiographic screening efforts among the civilian population following the war, including mass screening of asymptomatic individuals and routine hospital admission chest films.