Founded in the early 1960s by E.T. "Jack" Horn, the company was originally a distributor of raw materials to the coatings industry. In 1969, the company moved to a forty-thousand square foot building in La Mirada, California, which today acts as the company’s headquarters, and the hub of its corporate campus.

During the early seventies, the philosophy and practice of partnering with key suppliers became the cornerstone of a successful E.T. Horn distribution strategy. This approach involves providing its supplier partners full disclosure of the company's sales and marketing activities. This was a radical idea decades ago, but is now considered common practice in any successful distributor/supplier relationship. This special bond between supplier and distributor has been one of the most critical contributing factors to E.T. Horn establishing itself as one of the nation’s preeminent specialty chemical distributors.

As an employee owned business, the E.T. Horn Company has enjoyed exceptional growth over the past few decades, concentrating on the distribution of raw materials that require a sales force with both technical and industry knowledge. The company has continued to develop its partnering concept, extending it to customers as well as additional suppliers.