Which president was a charity director and an engineer miner?

Herbert Hoover, the 31st President of the United States, was both a charity director and an engineer miner. Before his presidency, he gained fame for his humanitarian efforts during World War I, particularly in organizing food relief for Belgium and later serving as the director of the American Relief Administration. Additionally, Hoover had a successful career as a mining engineer, working in various countries and contributing to the development of mining operations.