Square D

Square D
Company type	Subsidiary
Industry	Electrical equipment manufacturing
Predecessor	McBride Manufacturing Company
Founded	December 15, 1902; 123 years ago in Detroit, Michigan, United States
Founder	Bryson Dexter Horton, James B. McCarthy
Headquarters	Andover, United States
Area served	Worldwide
Key people	Bryson Dexter Horton (founder and president until 1928)
Products	Electrical equipment, circuit breakers, enclosed control panels, safety switches, panelboards
Owner	Schneider Electric
Number of employees	18,500 (1991)
Parent	Schneider Electric

Square D is a U.S.-based producer of electrical equipment with its main office located in Andover, Massachusetts. It operates as a prominent brand under the ownership of Schneider Electric, which purchased the firm in 1991.

Before being acquired, the company was listed on the New York Stock Exchange for over five decades. Throughout this period, it consistently avoided any quarterly financial losses and distributed dividends for 220 consecutive quarters.

History

The business was established on December 15, 1902, by Bryson Dexter Horton and James B. McCarthy, officially incorporating in 1903 under the name McBride Manufacturing Company. It broadened its product range within electrical components and rebranded as Detroit Fuse and Manufacturing in 1908. Horton, who graduated in electrical engineering from the University of Michigan, created the safety switch—an enclosed high-voltage switch device—that became central to the company’s offerings, including circuit breakers and enclosed control panels. The initial enclosed safety switch was introduced in 1909.

In 1917, after adopting a logo showcasing a capital "D" (symbolizing Detroit) inside a square shape, the company secured trademark rights for this design and changed its name to Square D. Horton held the position of president until 1928.

During the early 1920s, Square D sold off most of its fuse operations to concentrate on safety switches and associated products. This shift capitalized on increasing industrial safety concerns through marketing efforts such as the "Jones is Dead!" campaign.

By 1929, Square D merged with a Milwaukee-based industrial controller company and began manufacturing circuit breakers under license from Westinghouse. In 1935, it launched its proprietary circuit breaker series targeting both commercial and residential customers.

Throughout World War II, Square D supplied approximately half of all circuit breakers utilized in military aircraft.

In 1955, the company introduced a three-quarter-inch circuit breaker that replaced traditional removable fuses with safer and more user-friendly switch-based protection devices. Additionally, it developed panelboards designed to house multiple breakers. These advancements became widespread standards in residential and commercial installations by the turn of the century.

Square D shifted its headquarters from Detroit to Park Ridge, Illinois in 1960 and later expanded to a larger facility in Palatine, Illinois in 1979 as part of its global growth strategy.

Following its acquisition by Schneider Electric in 1991, Square D employed around 18,500 individuals and generated global sales totaling $1.65 billion.

In celebration of their combined centennial in 2003, Square D and Schneider Electric donated a working original enclosed safety switch from 1922 to the Smithsonian Museum.

Currently, Square D manufactures a variety of circuit breaker product lines serving residential, commercial, and industrial markets.

External links

Square D products at Schneider Electric