The origin of the SQUARE D name is legendary. In 1915, the Detroit
Fuse and Manufacturing Company introduced a stamped steel version of its enclosed
safety switch. Embossed on the
switch cover was a square with a capital 'D' for Detroit. The
safety switch became so popular that customers requested the 'Square D'
safety switch. Two years later, the company, capitalizing on the market demand for this product, changed its name to Square D Company. Today, the SQUARE D brand name remains one of the few created by its customers. in 1991, Schneider
Electric acquired Square D Company and added one of the most highly recognized and well-respected brands in the electrical industry to its portfolio.