Clarkson is an unincorporated community in Columbiana County, Ohio, United States.
Clarkson is located at 40°44′50″N 80°36′47″W / 40.74722°N 80.61306°W (40.7470065, -80.6134048). The majority of residences are clustered at the intersection of Clarkson and Sprucevale Roads (County Highways 426 and 428).
Clarkson was laid out and founded in February 1806 by Robert Hanna, who moved there in a conestoga wagon with his wife. It was surveyed by William Heald. Hanna built and resided in a log tavern at the intersection of two roads. This building was later known as the Edward McGinnis tavern.
A post office was established in Clarkson in 1833 and remained until 1935.
An early settler and businessman was Milo Warrick who, in 1840, was a cabinet maker and undertaker in Clarkson. His son, Clement Vlandingham Warrick, opened a general store in Clarkson in 1885. He established the first Standard Oil dealership in Ohio, holding vendor's license Number 1. 
Gaston's Mill, named for Clarkson resident Philander Gaston, lies within Beaver Creek State Park. The mill was built in 1837 and has been restored.
In 1817, James Monroe, while President of the United States, visited his cousin, Catherine Hanna, in Clarkson.
Pretty Boy Floyd, bank robber, was shot and killed by FBI agents in a corn field near Clarkson in 1934.
- ^ a b "US Board on Geographic Names". United States Geological Survey. 2007-10-25. http://geonames.usgs.gov. Retrieved 2008-01-31.
- ^ U.S. Geological Survey Geographic Names Information System: Clarkson, Ohio
- ^ a b Gaston, Philander. "Pioneer days of the little rural center of Clarkson [Columbiana County, Ohio, 1816-1873];portrayed by Philander Gaston (one of the oldest residents).". http://www.worldcat.org/wcpa/oclc/18826891?page=frame&url=http://acpl.aquabrowser.com/%26checksum%3Ddf9900d6f2b45ae57f45cc93a698505d&title=Allen+County+Public+Library&linktype=opac&detail=IMF:Allen+County+Public+Library:Public+Library.
- ^ Croly, Herbert David (1912). Marcus Alonzo Hanna: his life and work. The Macmillan Company. pp. 3. http://books.google.com/books?id=V-MEAAAAYAAJ&dq=%22Marcus+Alonzo+Hanna%22&source=gbs_navlinks_s.
- ^ a b Rice, Charles Elmer (1905). A history of the Hanna family: Being a genealogy of the descendants of Thomas Hanna and Elizabeth (Henderson) Hanna, who emigrated to America in 1763 (Google eBook). A. Pim & son. http://books.google.com/books?id=1U5PAAAAMAAJ&dq=%22Robert+Hanna%22+Clarkson&source=gbs_navlinks_s.
- ^ "Clarkson Post Office (historical)". Geographic Name Information System (GNIS). USGS. http://geonames.usgs.gov/pls/gnispublic/f?p=154:3:3064288333863119::NO:3:P3_FID,P3_TITLE:1967499,Clarkson%20Post%20Office%20(historical). Retrieved 26 February 2011.
- ^ "89-Year Old Storekeeper Sets a Mark". Youngstown (Ohio) Vindicator. February 21, 1953.
- ^ "Beaver Creek State Park". Ohio Department of Natural Resources. http://www.dnr.state.oh.us/parks/parks/beaverck/tabid/714/Default.aspx. Retrieved 27 February 2011.
- ^ "Kansas City Massacre—Charles Arthur "Pretty Boy" Floyd". Federal Bureau of Investigation, United States Government. http://www.fbi.gov/about-us/history/famous-cases/kansas-city-massacre-pretty-boy-floyd. Retrieved 26 February 2011.
- ^ Burrough, Bryan (2009). Public Enemies: America's Greatest Crime Wave and the Birth of the FBI, 1933-34. Penguin. ISBN 978-0-14-311586-1. http://books.google.com/books?id=7nGGEf3u_OMC&dq=%22Pretty+Boy+Floyd%22+Clarkson&source=gbs_navlinks_s.