St. Clair County is the oldest county in Illinois; its western border is formed by the Mississippi River, bordering Missouri. It is a part of the Metro East in southern Illinois. According to the 2020 United States Census, it had a population of 257,400, making it the eighth-most populous county in Illinois and the most populous in the southern portion of the state. Its county seat is Belleville. The county was founded in 1790 by the government of the Northwest Territory, from the western half of Knox County, before the establishment of Illinois as a state as the base for the Illinois Territory. Cahokia Village in the county was founded in 1697 and was a French settlement and former Jesuit mission.
Monroe County is a county located in the U.S. state of Illinois. According to the 2020 census, it had a population of 34,962. Its county seat and largest city is Waterloo.
Columbia is a city mainly in Monroe County with a small portion in St. Clair County in the U.S. state of Illinois, about 12 miles (19 km) south of St. Louis, Missouri. The population was 10,999 at the 2020 census.
This is a list of properties and districts in Illinois that are on the National Register of Historic Places. There are over 1,900 in total. Of these, 85 are National Historic Landmarks. There are listings in all of the state's 102 counties.
This National Park Service list is complete through NPS recent listings posted September 9, 2022.
This is a list of the National Register of Historic Places listings in St. Clair County, Alabama.
The following is a list of Registered Historic Places in St. Clair County, Michigan.
This National Park Service list is complete through NPS recent listings posted September 9, 2022.
This is a list of the National Register of Historic Places listings in Sanilac County, Michigan.
The Gustave Koerner House is a historic house located at 200 Abend Street in Belleville, Illinois. The Greek Revival house was built in 1848-49 and rebuilt in 1854–55 after a fire. Gustave Koerner, a German immigrant and prominent Illinois politician, lived in the house from its construction to his death in 1896. Koerner served as Lieutenant Governor of Illinois, sat on the Illinois Supreme Court, and was a member of the Illinois House of Representatives. He was also a political ally of Abraham Lincoln during his senatorial and presidential campaigns and convinced many German-American voters to support Lincoln. During the Civil War, Koerner served as United States Minister to Spain and thereafter mounted a failed campaign for Governor of Illinois.
This is a list of the National Register of Historic Places listings in Clermont County, Ohio.
This is a list of the National Register of Historic Places listings in Highland County, Ohio.
This is a list of the National Register of Historic Places listings in St. Clair County, Illinois.
This is a list of the National Register of Historic Places listings in Perry County, Ohio.
This is a list of the National Register of Historic Places listings in Vinton County, Ohio.
This is a list of the National Register of Historic Places listings in Union County, Ohio.
Bald Mound is an unincorporated community in Blackberry Township, Kane County, Illinois, United States, located at the junction of County Routes 10 and 78, 4.9 miles (7.9 km) west of Batavia. The Stearns-Wadsworth House, which is listed on the National Register of Historic Places, is located in Bald Mound.
Mount Pleasant is an unincorporated community located largely in St. George's Hundred, New Castle County, Delaware, United States. Mount Pleasant is located at the intersection of Delaware routes 71 and 896, north of Middletown. The A. Eliason House, north of town, is listed on the National Register of Historic Places.
State Park Place is an unincorporated community in Madison and St. Clair counties, Illinois, United States. State Park Place borders Collinsville to the east and Cahokia Mounds State Historic Site to the west.
The Pierre Martin House is a single-family French Colonial House and historic site in East Carondelet, Illinois about 1.5 miles (2.4 km) East of the Mississippi River. The house, built circa 1790, is owned by the Illinois Historic Preservation Agency. and located at the intersection of First Street and Old Route 3 in North Dupo.
St. Clair Springs is an unincorporated community and historic district in St. Clair County, Alabama, United States.
St. Marks is an unincorporated community in Sedgwick County, Kansas, United States. As of the 2020 census, the population of the community and nearby areas was 124. It is located about 4 miles (6 km) southwest of Colwich along 29th St N between 183rd St W and 199th St W, also it is located 5 miles (8 km) north of Goddard.
United States 
Illinois 
St. Clair 
