 Day & Zimmermann has an annual revenue of $2.5 billion, and is ranked by Forbes as one of the largest privately held companies in the United States.The company was founded in 1901 by Charles Day and Kern Dodge, son of James Mapes Dodge, as Dodge & Day, specializing in engineering, shop equipment and management.Later, the scope of the organization was enlarged to include a great deal of engineering and construction work in both the industrial and public-service fields.