Today I came across The History of Coles County, Illinois at the Internet Archive. There is quite a bit of material on the Parker family, albeit the wrong one. However, there is some information on my Parker line as well.
Another family of Parkers, and not related to those above mentioned, settled in this township in the winter of 1825-26, on what is called Parker Prairie, and from them the prairie received its name. George Parker and his sons, Samuel, Daniel, Jeptha and William Parker composed this settlement. They were originally from Butler County, Ohio, and removed to Crawford County, 111., in 1817, locating south of Palestine, where they remained until their settlement in this town, on Parker Prairie. Samuel Parker went back to Crawford Countv and died there, some of them died here, and Daniel and Jeptha are still living in the township, prominent farmers. George Parker is said to have entered the first land in Coles County.
In 1826, a settlement was made by the Parkers on what was known as Parker’s Prairie, and which lies partly in Hutton Township. George Parker and his sons Joseph, Daniel and Jephthah were the first in this immediate neighborhood, and from them this beautiful prairie received its name.
Joseph Parker killed a large bear, in 1828, near Buyess Berkley’s, and many other members of the Bruin family were slaughtered in an early day by the pioneers.