Work was resumed by the East Tennessee and Georgia Railroad (ET&G) in 1849, and by the mid-1850s rail lines connected Chattanooga, Knoxville, and the Tri-Cities.

A number of communities sprang up along the railroads in subsequent years, most notably Etowah, where the L&N built a large depot in the early 1900s, and Englewood, which developed into a textile manufacturing center in the late 19th and early 20th centuries.

[1] Like many East Tennessee counties, McMinn was polarized by the Civil War and the issue of secession.

[3] On August 18, 1920, State Rep. Harry T. Burn of Niota cast the deciding vote in the Tennessee General Assembly to ratify the Nineteenth Amendment.

McMinn County voters, although divided on the women's suffrage issue, reelected Burn to the state legislature three months later.

A group of World War II veterans launched an armed assault on the jail in Athens, where the county officials had retreated with the ballot boxes.

After an exchange of gunfire, the county officials turned over the ballot boxes, and the votes were counted in a public setting, proving the bipartisan reform ticket won the election.

[5][6] On December 11, 1990, a crash involving 99 vehicles occurred along Interstate 75 near Calhoun in heavy fog, killing 12 and injuring 42.

[7][8] The accident, which occurred in an area prone to fog, was reportedly the largest motor vehicle crash in United States history at the time, in terms of the number of vehicles involved, and was blamed by some on the nearby Bowater (now Resolute Forest Products) paper mill.

As of the 2020 United States census, there were 53,794 people, 20,804 households, and 13,685 families residing in the county.

The racial makeup of the county was 91.96% White, 3.95% Black, 0.34% Native American, 0.74% Asian, 0.02% Pacific Islander, and 1.79% from two or more races.

The 1870 Tennessee constitution prevented black and white children from attending the same public schools.

[25] After the Civil Rights Act of 1964 was passed, Tennessee began to integrate schools.

Furthermore 34% of high school students tested at or above the proficient level for reading, and 22% did so for math.

[29] Following Trump in the county vote were Democrat Joe Biden, Libertarian Jo Jorgensen, coal mining business executive Don Blankenship, and rapper Kanye West.