Transportation was always the key to the success of Lexington. The city got its start as a rest stop on the Chicago Trail, which was part of the larger Pontiac Trail between Chicago and St. Louis. The very first mention of Lexington's name in the press in 1836 included mention of the town's location on the stagecoach road between Springfield and Chicago. Lexington's success as a town was later assured when it became a railroad station between Springfield and Chicago. During the twentieth century, rail traffic slowly declined and was replaced by road traffic. By World War II, only two trains a day stopped at Lexington, and all passenger traffic by rail ended in 1946.
In 1915, a paved road along the former stagecoach route, which almost exactly paralleled the Chicago and Alton Railroad rail line, reached Lexington. This paved road was known as State Bond Route 4 or SBI 4, and it followed the Pontiac Trail between Chicago and St. Louis. In November 1926, there was a general renumbering of state highways following the creation of the U.S. Route System, and Route 4 became Route 66. For the next 50 years, Lexington was a popular stopping point on this famous American road. In 1955, U.S. Route 66 was locally widened to four lanes, as a partially divided highway with a grass median between the northbound and southbound lanes along much of its stretch. U.S. Route 66 served the community until 1978, when Interstate 55, which also closely paralleled the old highway, was opened to traffic and Route 66 was thereafter decertified. However, near Lexington, much of the old highway may still be driven, as the 1955 roadbed of the southbound lanes was retained as a two-lane county road (the disused northbound lanes remain nearby).
The population estimate as of 2016 is 2,048