Originally established in the 1890's by Patrick Edward O'Hair as a hardware business, P.E. O'Hair & Company evolved into a major wholesale supply enterprise, providing plumbing, heating, air conditioning, tools and industrial products to a growing California.

Following Patrick's death in 1923, the company was incorporated in 1932 and managed by three generations of P.E. O'Hair's descendants. In 1988, the descendant's of P.E. O'Hair sold the company to United Westburne for nearly $70 million. At the time of the sale, P.E. O'Hair & Co. had 14 branches, 460 employees, and $160 million in annual sales.