Harry Truman = Haberdashery business; vice president when FDR died
Jimmy Carter = Peanut farmer; governor of Georgia
Herbert Hoover, a man unjustly slandered for his government service, was a professional mining engineer, and as such, attempted to apply business principles to government operations. He was prominent in the relief efforts in Europe after the First Wold War, and served in Cabinet positions before ascending to the Presidency in 1928. He is most remembered for “causing” the Great Depression, but that was by all objective standards, not really in the “Great” category until FDR was elected to “fix” things. The United states was in worse economic shape in 1920, coming off the First World War, under Harding, but swiftly recovered, using the same sort of measures taken by Ronald Reagan some 60 years later.