Garden Prairie is an unincorporated former village and census-designated place located in Boone County, Illinois, United States. It is part of the Rockford, Illinois Metropolitan Statistical Area. Garden Prairie was originally called Amesville, in honor of a pioneer settler. The present name refers to the fertility of their surrounding land on the prairie. A post offi…Garden Prairie is an unincorporated former village and census-designated place located in Boone County, Illinois, United States. It is part of the Rockford, Illinois Metropolitan Statistical Area. Garden Prairie was originally called Amesville, in honor of a pioneer settler. The present name refers to the fertility of their surrounding land on the prairie. A post office was established as Amesville in 1838, and renamed Garden Prairie in 1853.