The Dunleith & Dubuque Bridge Company was originally founded in 1868. The company operated the original Dubuque Rail Bridge, a swing bridge constructed by Andrew Carnegie. The bridge opened in December of 1868, and was primarily used by the Illinois Central Railroad.

The Dubuque Rail Bridge was rebuilt in the 1890s and has 5 spans and a swing-span. Because of a 150-foot bluff very close to the Mississippi riverbank on the Illinois side, the railroad tracks enter a 1/4-mile tunnel that curves 90-degrees to the south to allow trains to proceed along the tracks adjacent to the river south of the bridge.

At least two famous men at one time worked for this important railroad bridge company – James A. Roosevelt (FDR’s father) and General Caleb Hoskins Booth (who help found the company). Booth was one of Iowa’s most successful businessmen, and was the first mayor of Dubuque.