"Mount Pleasant" or the Newcomer Farm

Laid out in 1763 by Joseph Chapline, Sharpsburg may be the oldest town in Washington County, Maryland. English and German settlers had begun arriving the the area by the 1730s, often following the "Great Wagon Road" from Philadelphia through a pass in South Mountain and down the Great Appalachian Valley into Maryland and Virginia. Chapline started selling town lots just after the conclusion of the French and Indian War (part of the globe-spanning Seven Years' War), and he named the town after Maryland's propriatary governor Horatio Sharpe. 

Christian Orndorff (Junior) was one of those German settlers who re-emigrated from Pennsylvania, and he started a farm and milling business beside the Antietam Creek that he called "Mount Pleasant." Orndorff supported Revolutionary forces during the way and helped to alert officials in Hagerstown and Frederick of a Loyalist conspiracy in 1781, which resulted in the arrest of Henry Newcomer, possibly the grandfather of Joshua Newcomer who later bought Mount Pleasant.

The Orndorffs sold the Mount Pleasant property in the early 19th century and Joshua Newcomer purchased it in 1853. During the Battle of Antietam, the farm buildings beame hospitals and the Newcomer's crops were destroyed.  While the house and barn still stand, the mill was destroyed sometime after operations ceased in the 1880s.

Newcomer Farm at the Antietam Battlefield National Park Service website