Malaria was an American disease, endemic across the South and Mississippi Valley, and its biggest legacy is an institution: the CDC. To protect Army camps in World War II the Public Health Service set up a malaria control office in Atlanta in 1942, which Joseph Mountin reorganized in 1946 into the Communicable Disease Center. The U.S. declared malaria eliminated in 1951, though it was already falling before DDT.
Malaria was already in steep decline before the DDT program, because of drainage, screening, better housing, and out-migration, so DDT finished the job rather than won the war alone. Elimination of local transmission differs from global eradication, and DDT was later restricted for ecological harm.