The Forest City
The inspiration for the name is a reference to Cleveland, describing a highly sophisticated society amid a heavily forested environment in Alexis de Tocqueville's Democracy in America, which contains the Frenchman's observations of the United States in the 1830s. Early use of the moniker is uncertain. Some say that Timothy Smead, editor of the short-lived Ohio City Argus first put the name to use. Many others believe that William Case, secretary of the Cleveland Horticultural Society and Cleveland's mayor from 1850 to 1851, carried the name forward. Case was well known for encouraging the planting of fruit trees, and thus the name stuck.
In the late 1860s, the city's best baseball club adopted the name, became an independent professional team in 1870, and helped found the first professional league, the National Association, in 1871. The first National Association game was a visit by the Forest City club of Cleveland to the Kekionga club of Fort Wayne, Indiana on May 4, 1871. It is considered the first major league baseball game by those who count the National Association as a major league. The team folded after the 1872 season. During 1871, it was one of two National Association teams named "Forest City", the other being a team based in Rockford, Illinois.
Other cities 
Rockford, Illinois, also is nicknamed "The Forest City." A professional baseball team named Forest City was based in Rockford; it existed for one season, in 1871, and played in the National Association. It was one of two teams of the name in the National Association that year, the other being the Forest City club based in Cleveland, Ohio.