ESP was founded in 1965 as E-S Precision Molded Products, in Melrose Park, Illinois with one injection molding machine.  

The “E” and the “S” were the first initials of the founders last names.  In 1967, the plant was relocated to McHenry, Illinois and six years later, in 1973, moved again to Burlington, Wisconsin. In 1980 a new facility was built at the current location at 809 Mohr Ave, with a total of  10,000 sq. ft. On January 1, 1987, the company was purchased by Burton Keddie and the name was changed to E-S Plastic Products.

Building growth of E-S Plastics includes:
1989 - 15,000 sq. ft. addition for molding, tool room, finishing, and warehouse
1991 - 22,500 sq. ft. addition for new molding floor, QC lab, lunchroom, and day care center
1999 - 13,000 sq. ft. addition for warehousing raw materials and finished goods

Currently, E-S Plastics has 25 molding presses in 60,000 sq. ft. with presses ranging from 28 up to 606 tons