For many millennia, the Great Plains of North America was inhabited by nomadic Native Americans.

In 1802, Spain returned most of the land to France, but keeping title to about 7,500 square miles.

In 1803, most of the land for modern day Kansas was acquired by the United States from France as part of the 828,000 square mile Louisiana Purchase for 2.83 cents per acre.

It was named in honor of William Allen, a United States senator from Ohio.

[3] Richard J. Fuqua and his family are considered the first white settlers in the county, arriving in the valley of the Neosho River January 1855.

Parsons arrived in March of the same year and selected claims in the valley of the Neosho River, near the mouth of Elm Creek.

The anti-slavery population expressed such antipathy toward their pro-slavery neighbors that slaves within the county there were either freed or taken elsewhere in Kansas by their masters.

In the spring of 1855 pro-slavery settlers from Fort Scott laid out the town in a hilly area east of the Neosho River and south of the mouth of Elm Creek.

The territorial legislature passed an act in July 1855 incorporating the Cofachique Town Association.

Another possible contribution to the town's decline involved tensions between the pro and anti-slavery settlers.

The St. Laurence newspaper reported: "No rain, no snow, and much open, thawing, mild weather, alternated with sharp, though brief [cold] snaps..."[8] Most of the people who had moved to the county in the previous two years were still trying to establish their farms.

The general surface of the country is slightly rolling, though much more level than the greater portion of eastern Kansas.

The bottom lands along the streams average one and one-half miles in width, and comprise one-tenth the area of the county.

The principal varieties of trees native to the county are black walnut, hickory, cottonwood, oak, hackberry and elm.

[4] The main water course is the Neosho River, which flows through the western part of the county from north to south.

During the years of the American Civil War the county continued to develop though at a slower rate.

[citation needed] The population increase during the 1890/1910 period was likely due to the oil and gas discoveries and production near Iola.

Outside the county the route connects to Fort Scott in the east and Yates Center and eventually Wichita in the west.

The segment between Iola and Chanute is a freeway with fully controlled access, although there is only one lane in each direction.

† means a community is designated a Census-Designated Place (CDP) by the United States Census Bureau.