New Sewickley Township is a part of Depreciation Lands that were set aside by Act of Assembly on March 12, 1783, to be awarded to those men who served in the American Revolutionary War.

At that time, New Sewickley Township was situated in the eastern part of Beaver County and was composed of about 19,279 acres (78.02 km2) of hilly, but very fertile land.

Despite being bordered by Cranberry township the area is still predominantly rural.

According to the United States Census Bureau, the township has a total area of 32.7 square miles (84.7 km2), all land.

19.6% of all households were made up of individuals, and 8.3% had someone living alone who was 65 years of age or older.