The Eli Bridge Company manufactures and supplies Ferris Wheels and other amusement park rides, such as the Scrambler. The company was founded by William Eli "W.E." Sullivan (1861-1932) as the Eli Bridge and Iron Company sometime prior to the 1893 Chicago World's Fair. The family-owned business changed its focus due to W.E. Sullivan's fascination with the 250-foot rotating wheel built by Pittsburgh bridge builder George W.G. Ferris (1859-1896). Ferris designed and built the structure to compete with the Eiffel Tower, the centerpiece of the 1889 World's Fair in Paris. Sullivan wanted to create a smaller, portable version of the Ferris Wheel that could be transported from carnival to carnival.

After attending the fair, Sullivan returned to his hometown of Roodhouse, Illinois, and partnered with machinist James H. Clements (1868-1935). On May 23, 1900, the 45-foot portable Ferris wheel called the "Big Eli" debuted in Jacksonville, Illinois. Sullivan officially incorporated his company as the Eli Bridge Company in 1906.

The company began producing a variety of different Big Eli models. In 1919, after several expansions, the Eli Bridge Company relocated its headquarters from Roodhouse, Illinois, to a larger plant in Jacksonville, Illinois. The factory is still located there today.

In 1955, the company debuted its first non-wheel attraction, the Scrambler. The ride features a double-rotating, carriage-like car suspended from a center hub. The ride is a staple among amusement parks.

W.E. Sullivan married Julia Lou Crayne (1864-1962) in 1883; the couple had three children. Their eldest son, Lee A. Sullivan (1889-1968) became chief operating officer after his father's death. Lee Sullivan married Nell Griffiths (1891-1957) in 1916; they also had three children. The youngest son, Lee A. Sullivan Jr. (1925-2016) was a licensed professional engineer and served as president and board chair of the Eli Bridge Company, where he was involved in its leadership from 1950 until his death. He was nationally known throughout the amusement ride industry and advocated raising safety standards. In 1949, he married Barbara June Bienemann (1926-1998); the couple had five children, at least two of whom are active in the company today.