Adler, professional engineer and inventor, resided in Baltimore, Md., all his life. At 14 he patented an electric automotive brake. After attending Johns Hopkins University and serving briefly in the Army, he joined the Maryland and Pennsylvania Railroad, developing safety devices. In 1928 he developed the first sound-activated (by auto horn) traffic signal. Was granted over 60 U.S. patents (of which he donated 10 to the Government), was a licensed pilot and a member of numerous professional engineers' societies. Member, Maryland State Aviation Commission, 1953-1959; served on the Maryland Traffic Safety Commission from 1952 until his death.
Contains much biographical information on Adler and his career. Newspaper clippings, photographs and other memorabilia detail his activities. Adler's published writings include articles in periodicals and newspapers. Numerous patent applications, related correspondence and royalty receipts relate to his inventions.
Charles Adler, Jr. Collection, ca. 1920-1980, Archives Center, National Museum of American History