Logan was one of fifty Virginia counties that became part of the new state of West Virginia in 1863, by an executive order of Abraham Lincoln during the Civil War, even though Logan County had voted for secession in the April 4, 1861, convention.

Within months of its admission to the Union, West Virginia's counties were divided into civil townships, with the intention of encouraging local government.

This proved impractical in the heavily rural state, and in 1872 the townships were converted into magisterial districts.

The county was redistricted again in the 1980s, resulting in nine magisterial districts: Buffalo, Chapmanville, East, Guyan, Island Creek, Logan, Northwest, Triadelphia, and West.

More recently, the Buffalo Creek Flood of February 26, 1972, killed 125 people when a coal slurry dam burst under the pressure of heavy rains, releasing over 100,000,000 US gallons (380,000,000 L) of waste and water in a 30-foot (9.1 m) wave onto the valley below.

As of the 2010 United States census, there were 36,743 people, 14,907 households, and 10,512 families living in the county.

[15] Logan County, being historically secessionist[16] and between the New Deal and the 1990s heavily unionized, was once powerfully Democratic.

Before the 2008 presidential election, the only Republican to carry the county had been Herbert Hoover in 1928, due to strong anti-Catholicism against Al Smith in this "Bible Belt" region.

From 2000 to 2016, the county swung more Republican in each consecutive election, due to the Democratic Party's support for environmentalist policies.

[17] Democratic vote shares since 2016 have plummeted to levels historically more typical of unionist, traditionally Republican counties like Grant.