Clayton Mark founded Clayton Mark and Company in 1900 in Evanston to manufacture wrought steel pipe and water well supplies. Clayton Mark, along with his four sons Clarence Mark, Clayton Mark,
Cyrus Mark, and Griffith Mark held various positions in the firm and made it a driver of Evanston's economy. It was the single largest employer in the city, with overall sales exceeding $10,000,000 a year. ==References==