After graduating from Peirce School of Business Administration, Guggenheim relocated to Pueblo, Colorado, where he worked as the chief ore buyer at M. Guggenheim's Sons, his father's mining and smelting company.
After his U.S. Senate term expired, he and his wife Olga returned to New York City. Guggenheim joined the board of American Smelting and Refining Company, and was later appointed chairman of the board. From 1919 to 1941, he was the company's president.[6]
Personal life
After moving to Denver in 1892, Guggenheim married Olga Hirsch on November 24, 1898, at the Waldorf Astoria New York in Manhattan. To celebrate their marriage, the Guggenheims provided a Thanksgiving dinner to 5,000 poor Manhattan children.[3]
Their first child, John Simon Guggenheim, was born in 1905. To commemorate the event, Simon Guggenheim made an $80,000 donation (equivalent to $2,700,000 in 2023) to the Colorado School of Mines to build a namesake building, Simon Guggenheim Hall. At the time, it was the largest private grant ever made to a state institution.[7]
In 1907, Olga gave birth to their second son, George Denver Guggenheim. In 1909, Simon donated a law school building at the University of Colorado.[8]