1139 Clarkson Street was built in 1902 (permit #281, March 4th, 1902) for Charles S. and Mary E. Card at a cost of $4500. No architect or builder is listed on the permit. Charles S. Card was born in 1868 in Ohio and first appears in Denver city directories in 1891.  Card was trained as a mechanical engineer and was president of the Card & Weber Machine Company at the time the house was constructed.  Card founded one of Colorado’s largest mining equipment suppliers, C.S. Card Iron Works Company, in 1907.  The company built a mine car, known as the Card Mine Car, used throughout the region, including in the construction of the Moffat Tunnel.