St. Jacob Township is located in Madison County, Illinois, in the United States. As of the 2010 census, its population was 2,578 and it contained 981 housing units.[2]
Geography
According to the 2010 census, the township has a total area of 35.95 square miles (93.1 km2), of which 35.6 square miles (92 km2) (or 99.03%) is land and 0.35 square miles (0.91 km2) (or 0.97%) is water.[2]