Decatur County was created by the act of the legislature of 1873. It is one of the northern tier of counties in the northwestern part of the State; ten counties lie between it and the Missouri River, two between it and Colorado. Its area is 900 square miles. The name of the county was given to it in commemoration of Commodore Stephen Decatur, who was born in Sinnepaxent, Md., and killed in a duel with Commodore James Barron, March 20, 1820, and who was a prominent actor in the war of 1812. Source: Cutler's History of the State of Kansas 

County Seat: Oberlin, Kansas

Date organized: December 11, 1879

County History:

Cutler's History of the State of Kansas,Decatur County 

Historic Landmarks, State, National:

Sappa Park & Wetlands

Bank of Oberlin, Kansas

County Historical Society: 

1. Last Raid Indian Museum
2. Jennings Czech Museum
3. Decatur County Kansas Genealogy

Websites about the county:

1. Oberlin and Decatur County Kansas
2. City of Oberlin Kansas
3. City of Norcatur
4. Decatur County on Skyways