St. Clair Township, one of thirteen townships in Butler County, Ohio, United States, consists of three disconnected pieces located along the Great Miami River in central Butler County. It had a population of 6,908 at the 2010 census, down from 7,336 in 2000. Exclusive of the village of New Miami and the southern part of the village of Seven Mile, which lie within its borders, the unincorporated portion of St. Clair Township had 4,404 inhabitants in 2010. History Creation One of the original five townships of Butler County, it was erected by the Butler County Court of Quarter Sessions on May 10, 1803, with these boundaries: Beginning on the west bank of the Miami at the southwest corner of the fractional township No. 1 of the fourth range west of the Miami; thence north to the northern boundary of the county; thence west to the northwest corner of the county; thence south to the southwest corner of the township No. 4 of the first range west of the Miami; thence east to the Miami; thence northeasterly and northwestwardly up the Miami to the place of beginning. Reduction The area of the township has been significantly reduced from the original boundaries. Four new townships were created from it: Milford Township and Wayne Township, both on December 2, 1805; Reily Township on December 7, 1807; and Hanover Township (from parts of St. Clair and Ross townships) on December 2, 1811. What is now Oxford Township was originally within the bounds of St. Clair Township, Oxford having been erected from Milford Township in 1811. From these reduced borders, which consisted of nineteen whole and nine fractional sections, a substantial area has been withdrawn from the township because of annexations by the city of Hamilton. Most of the area of Hamilton west of the Great Miami River, the township's southern boundary, was originally included in St. Clair Township. In 1857, a paper township, Hamilton, was erected from parts of St. Clair and Fairfield townships. Name It is named for General Arthur St. Clair, governor of the Northwest Territory before Ohio's statehood. Statewide, the only other St. Clair Township is located in Columbiana County. Historic population figures 1810—1,180 1820—1,307 1830—1,834 1850—2,602 1900—1,388 1910—1,955 1920—2,161 1930—3,225 1940—3,828 1950—4,950 1960—7,011 1970—7,952 1980—8,223 1990—7,670 2000—7,336 2010—6,908 Geography Located in the center of the county, it borders the following townships: Wayne Township - north Madison Township - east Fairfield