[4] The Maryland General Assembly chartered the town of Barnesville in 1811 and named it in honor of its earliest settler, Williams Barnes.

[5] In its early years, the village developed as a regional center for industry and commerce, with two taverns, a blacksmith shop, and a resident physician, a Dr.

[5] In the 1830s, Barnesville Academy operated on the Hays Farm under the leadership of Irish immigrant Thomas Carr Lannan.

[6] Jesuit Ministers from Frederick first held mass in Barnesville and led in the creation of St. Mary's Church in 1807.

[7] The church yard contains several graves from immigrant workers who died of cholera while building the Chesapeake & Ohio Canal.

Barnesville Baptist Church was organized in 1871 and still worships in its original frame building on the east side of the town.

According to the United States Census Bureau, the town has a total area of 0.49 square miles (1.27 km2), all land.

[8] The climate in this area is characterized by hot, humid summers and generally mild to cool winters.

At the top of a ridge with views of Sugarloaf Mountain to the north and the Catoctin Mountain and Blue Ridge ranges to the west, Barnesville enjoys a connection with the rhythms of the natural world while being within commuting distance to Washington, D.C.

Northeast of Barnesville, MD 109 interchanges with Interstate 270 and Maryland Route 355 in Hyattstown.