In April 1865, John Wilkes Booth made his escape through Charles County after shooting President Abraham Lincoln.

He stopped briefly in Waldorf (then called Beantown) and had his broken leg set by local Doctor Samuel Mudd, who was later sent to prison for helping him.

[10] Booth then proceeded to hide in the Zekiah Swamp in Charles County, avoiding search parties for over a week until he and his accomplice were able to successfully cross the Potomac River.

[10] The 1911 Digges Amendment, which attempted to disenfranchise African Americans in Maryland, was drafted by Democratic state delegate (lower house) Walter Digges and co-sponsored by state senator (upper house) William J. Frere, both from Charles County, Maryland.

Nationally Maryland citizens achieved the most notable rejection of a black-disfranchising amendment.

[11] In 1926, a tornado ripped through the county leaving 17 dead (including 13 schoolchildren).

On April 28, 2002, another tornado (rated an F-4) destroyed much of downtown La Plata killing 3 and injuring over 100 people.

[12] The county has numerous properties on the National Register of Historic Places.

On December 4, 2004, an arson took place in the development of Hunters Brooke, a few miles southeast of Indian Head.

[15][16][17] Owing to the considerable voting power of its large number of freedmen following the Civil War,[18] and later its growth as a suburban area, Charles County was for a long time solidly Republican.

Since the turn of the millennium, Charles County has become reliably Democratic, although not as overwhelmingly so as other parts of Maryland's Washington, D.C.

[24] In its western wing, along the southernmost bend in Maryland Route 224, Charles County contains a place due north, east, south, and west of the same state—Virginia.

[25] As of the 2010 United States Census, there were 146,551 people, 51,214 households, and 38,614 families residing in the county.