Muscle Shoals, a section of the Tennessee River in northwestern Alabama. Until dams transformed it into a chain of lakes, this part of the river consisted of a series of rapids, or shoals, extending 37 miles (60 km) upstream from Florence. During World War I the federal government began construction of a dam here to provide power for a fertilizer plant. The dam, named Wilson Dam, was completed in 1925.

In 1933 the newly created Tennessee Valley Authority (TVA) took over operation of Wilson Dam and the chemical plant, which later was developed into the TVA National Fertilizer Center. Wheeler Dam, about 15 miles (24 km) upstream, was completed in 1936. These dams impound lakes, provide electricity, improve navigation, and control floods.