From the record
“Glenwood School is a historic one-room schoolhouse at 1398 East 800 North Road in rural Ash Grove Township, Iroquois County, Illinois, near the village of Cissna Park. The school opened in 1887, shortly after compulsory public schooling laws in Illinois spurred a wave of rural school construction.”
Wikipedia article Glenwood School (Cissna Park, Illinois), CC BY-SA 4.0.
One of 7 National Register listings published here for Iroquois County · listed in 2020 · category: Building.
Sources: the Wikipedia article · the National Register database, National Park Service · the Wikipedia article