The town of Hartford was first called Gwynn when it was originally settled. Prior to 1900, the town saw the arrival of the Rock Island Railroad and the town's name was changed to Hartford. Hartford was incorporated in 1900 and as a result, the old original town of Hartford, about one and a half miles west and named for a creek crossing belonging to the Hart family, is now generally referred to as "Old Town" or "West Hartford". According to Goodspeed's "History of Arkansas", William J. Fleming and William Stevenson opened the first store in West Hartford. By 1891 there were several businesses, a public school, and a Union Church edifice used respectively by Methodists, Baptists, and Cumberland Presbyterians.
The town of Hartford was incorporated February 28, 1900.
During the early half of the twentieth century, the town was home to the Hartford Music Company, which operated a singing school and also published Gospel songs with "I'll Fly Away" and "Victory In Jesus" being two of the most widely known. The city was also home to significant mining activity, which has returned to a limited extent.
Hartford High School was the first school in Arkansas with a lighted football field.
The Hartford School District was annexed by the Hackett School District in 2015.