E&J DeMARK was founded in 1984 by Ed Hecock and Jim Mumper, with initial operations taking place in a garage attached to a residence in Wauseon, Ohio. Their objective was to provide the utility and phone industries with cutting-edge electrical grounding gear and supplies.

By consistently developing top-notch, convenient equipment and accessories, E&J DeMARK has expanded and become well-known in various markets over the years. DeMARK now has eight electrical product lines and four US patents.

Jim Mumper made the decision to leave E&J DeMARK in 1992, and Ed Hecock started the shift to internal manufacturing and distribution. DeMARK purchased its current Wauseon location at 1115 North Ottokee St. in 1995 after outgrowing its garage.