The township is in northwestern Jefferson County and is bordered to the west by Clarion County. The borough of Corsica, a separate municipality, lies along the county line and is bordered to the north, east, and south by Union Township. Roseville is an unincorporated community in the eastern part of the township. Interstate 80 crosses Union Township, with access from Exit 73 just north of Corsica. U.S. Route 322 runs south of and parallel to I-80, passing through Corsica and Roseville. According to the United States Census Bureau, the township has a total area of, of which, or 0.08%, are water. The township is bordered to the north by Mill Creek, a west-flowing tributary of the Clarion River. The entire township is in the Allegheny River watershed.
Demographics
As of the census of 2000, there were 816 people, 323 households, and 249 families residing in the township. The population density was 45.9 people per square mile. There were 401 housing units at an average density of 22.6/sq mi. The racial makeup of the township was 99.75% White, and 0.25% from two or more races. Hispanic or Latino of any race were 0.37% of the population. There were 323 households, out of which 30.3% had children under the age of 18 living with them, 65.9% were married couplesliving together, 6.2% had a female householder with no husband present, and 22.9% were non-families. 20.7% of all households were made up of individuals, and 9.3% had someone living alone who was 65 years of age or older. The average household size was 2.53 and the average family size was 2.90. In the township, the population was spread out, with 22.1% under the age of 18, 8.2% from 18 to 24, 26.7% from 25 to 44, 26.0% from 45 to 64, and 17.0% who were 65 years of age or older. The median age was 41 years. For every 100 females, there were 102.5 males. For every 100 females age 18 and over, there were 102.5 males. The median income for a household in the township was $34,559, and the median income for a family was $38,828. Males had a median income of $29,318 versus $18,625 for females. The per capita income for the township was $15,528. About 4.6% of families and 7.2% of the population were below the poverty line, including 10.9% of those under age 18 and 6.2% of those age 65 or over.
