Donald George Wilhelm (January 23, 1887 - February 25, 1945) was a prolific author and lecturer in New England, and the grandfather of Bill de Blasio, the Mayor of New York City (2014-present). He was a member of the Cosmos Club in Washington and the Harvard Club in New York. He married Nina Warren.
He was born on January 23, 1887 in Defiance, Ohio, as the son of John C. Wilhelm and Agnes Marantitte. He was educated at George Washington and Harvard Universities. In 1917-1918, he collaborated with Benedict Crowell, assistant Secretary of War, on articles fostering a united air service, and also served on President Woodrow Wilson's United States committee on public information for the Advisory Council of National Defense. In 1923, he served as a personal assistant to Herbert Hoover, then Secretary of Commerce, to study industry in the Ukraine, the Crimea, the Ruhr Valley, and England.
In the fall of 1942, Wilhelm traveled to England during World War II as a war correspondent gathering magazine material. He had made a first-hand study of United States arsenals and war plants for the government. Among his articles on the war were "Boomtown No. 1," "What Happened at Wake?", and "Robot of Destruction" (on the torpedo). His books included, "The Book of Metals," "Story of Iron and Steel," and "Writing for Profit."
He moved to Riverside in Greenwich, Connecticut, and remained there during World War II after his time in England. On February 25, 1945, he died of a heart attack in Brooklyn, New York, at the age of 58. He was survived by his wife, his children, a sister, and two brothers.