Born in 1838 at Hampstead Harbor, New York, Cheesman moved to Chicago in 1854 where he worked as a pharmacist. In 1860 he relocated to Denver in the Territory of Colorado, opening a drug store. Over the next decade his business prospered and Cheesman began to invest in a number of other ventures, including railroads, mines, and irrigation companies. He died in Denver in 1907. Much of the material in this collection pertains to his investments in a number of mining companies in Colorado.