JG Companies was founded 40 years ago in 1979 by Jack Grothe. Jack started the business in his home in Diamond Bar with the office in the living room and the warehouse in the garage. Jack started as an Electrical and General Contractor doing TI work and smaller construction jobs. Over the years JG had offices in Walnut and Chino and about 18 years ago the Corporate Office on El Prado was built. Over the years JG has become licensed in 11 Western states so we could service our multi-state customers. In 2014, Jack and June sold JG to the ESOP so all JG employees could participate in owning a part of the company.