During the 19th century Middletown experienced continued residential and commercial growth until the Civil War. Many skirmishes took place in the area during Jackson's Valley campaign. The 1864 Battle of Cedar Creek, which began just south of the town limits before moving north through the town, resulted in many damaged properties. Commerce increased after a railroad track built in 1870 helped the town recover from the war's effects. Many of the town's historic houses were constructed in the late-19th century.
