The Harrington-Seaberg Corporation was founded in Moline, IL in 1920 by Fred Harrington and Severin Seaberg. The original company was known as the Harrington Machine and Electric Company and they primarily manufactured fire alarm boxes. In 1922 the company was getting contracts to install traffic signals in such places as Chicago and Los Angeles.

In 1923 the company changed its name to the Harrington-Seaberg and produced a line of traffic signals and beacons. Harrington-Seaberg was bought out by the Gamewell Corporation in 1929. Gamewell also owned Eagle Signal, and Eagle distributed Harrington-Seaberg signals until it introduced the Eaglelux in the early 1930s.

In the 1920s many signals followed the railroad signal convention that positioned green on the top and red on the bottom. All of Harrington-Seaberg's advertisements showed green on the top. (Many signals that were still in service after World War II had their lenses switched out to conform to the new national standard of red on the top and green on the bottom.)

The standard factory color for the signal was black. This signal was painted bronze in order to better show off the construction details. This signal was restored to its original "green on the top" configuration.