During the 20th century, it was often a center of labor strife between coal mine owners and union workers, especially in the Harlan County War of the 1930s.

Eastern Kentucky is believed to have supported a large Archaic Native American population in prehistoric times, and has sites of other cliff dwellings.

While archeology was not yet well-developed as an academic discipline, several professors from the University of Kentucky came to the site to excavate it and try to assess the finds.

Silas Harlan served under George Rogers Clark in the Illinois campaign of 1778–79 against the British; he commanded a company in John Bowman's raid on Old Chillicothe in 1779, and assisted Clark in establishing Fort Jefferson at the mouth of the Ohio River in 1780.

What was called the Harlan County War in the 1930s consisted of violent confrontations among strikers, strikebreakers, mine company security forces, and law enforcement.

After the Battle of Evarts, May 5, 1931, Kentucky governor Flem D. Sampson called in the National Guard to restore order.

Ballads sung on the picket line at the Brookside mine in Harlan County were captured on film by documentarian John Gaventa.

Blair In 1924, Conda Uless (Ulysses) "Condy" Dabney[12] was convicted in the county of murdering a person who was later found alive.

In 2007, the Ridgetop Shawnee Tribe of Indians formed as a non-profit organization to work on improving the lives of multiracial families and preserving Native American heritage, structures and artifacts in the area.

Now known as the Ridgetop Shawnee, they have become the heritage arm of Pine Mountain Indian Community, LLC, which since 2013 has taken the lead in working on economic development in the region.

Black Mountain, located east of Lynch, is Kentucky's highest point, with an elevation of 4,145 feet (1,263 m) above sea level.

The latter-twentieth-century decline of coal production and employment has led to widespread poverty and high unemployment.

[26] By 2016, more than half of the county's income came from transfers from the Federal government such as Social Security, Medicare and food stamps.

[27] As of 2018 new jobs are being located in the county as Teleworks USA has opened a hub in the city of Harlan.

In the 2016 election, its voters supported Republican nominee Donald Trump over Democrat Hillary Clinton by a 72.12% margin (84.87 to 12.75).

[30] In 2020 Donald Trump received 85.38% of the county's vote compared to 13.62% for Democratic nominee Joe Biden, for a slightly lower margin of 71.76%.

In the James Jones novel "From Here to Eternity", Robert E. Lee Prewitt, a bugler in the Army and the main character, is from Harlan County.

It has been covered by many artists from Pete Seeger and the Almanac Singers to Billy Bragg, the Dropkick Murphys, and Natalie Merchant.

It is mentioned in Robert Mitchum's recording "Ballad of Thunder Road" as a stop along a moonshine route.

It is the subject of the Darrell Scott song "You'll Never Leave Harlan Alive", which has been covered by Brad Paisley, Dave Alvin, Kathy Mattea, and Patti Loveless, among others, and has been heard in several versions on the TV drama Justified.

[46] Dave Alvin also wrote and performed his song, "Harlan County Line" for an episode of Justified.

The band Spear of Destiny included the song "Harlan County", on their 1985 album World Service.

Harlan County is mentioned in the Merle Travis song Nine Pound Hammer which he wrote in 1939; it has been covered by many bluegrass artists including Doc Watson.

Singer/Songwriter Loudon Wainwright III included a song titled "Harlan County" on his 2014 album I Haven't Got The Blues (Yet).

Harlan County is mentioned as the setting of the David Allan Coe song "Daddy Was A God Fearin' Man" in his 1977 album Tattoo.

The Cast Iron Filter song "Harlan County, USA" from the 2000 album "Further Down the Line" recounts a dramatization of the Eastover/Brookside coal miners' strike.