Located in Roscoe Township, Section 16
History of St. Clair Co., Missouri 1883:
Wyatt’s Grove, on the northwest quarter of the northeast quarter of Section 16, was the location of the county seat for two terms.
It was just north of this line, on Section 9, that the fight was made for the location of the county seat in 1841. Wyatt’s Grove was about a mile east
of present Roscoe.
Missouri History Encyclopedia, 1901:
St. Clair County was named for General Arthur St. Clair, of Revolutionary War fame. Its boundaries were defined by act of the General Assembly, January 16, 1833. February 11, 1835 it was attached to Rives (now Henry) County for civil and military purposes, and May 5, 1835 it was designated as St. Clair Township in that county. November 4th following, it was divided into two townships, named Weaubleau and Monegaw, and at an election held December 10th, James Gardner and Jesse Applegate were chosen justices of the peace for these townships respectively. The County of St. Clair was organized by act of the General Assembly February 15, 1841, and then included portions of the present Counties of Benton, Hickory and Cedar. Its present boundaries were established in 1845. Joseph Montgomery, Calvin Waldo and Thomas F. Wright were named commissioners to hold an election for location of a county seat. Osceola was chosen after a bitter contest, in which Jesse Applegate endeavored to secure the location at Wyatt’s Grove, about one mile east of the present village of Roscoe. The majority in favor of Osceola is variously stated at “seven and seventeen”. The Wyatt’s Grove party sought to overturn the election through court process, but their motion was overruled by Judge Foster P. Wright.