During the 1863 Gettysburg Campaign of the American Civil War, the township was a main thoroughfare for two invading forces of the Confederate Army.

Early's division marched east–west through the township en route to seize York.

Stuart's cavalry rode north–south through the township following the Battle of Hanover on their way to Dover.

West Manchester Township farmers and residents lost horses and mules to the Confederates.

The Samuel Stoner Homestead was added to the National Register of Historic Places in 1976.

27.8% of all households were made up of individuals, and 13.7% had someone living alone who was 65 years of age or older.

Voith Hydro and BAE Systems have factories in West Manchester Township.