Exact federal listing answer
Is Post House on the National Register?
Yes · NPS status: Listed
Yes. Reference 80001390 is listed.
Yes. The U.S. National Park Service listed-properties dataset through May 22, 2026 identifies Post House as Listed in the National Register of Historic Places under reference 80001390.
Federal statusListed
National Register reference80001390
Listed dateMay 28, 1980
Property categoryBuilding
Published address1516 State St.
LocalityAlton, Madison County, Illinois
Significance levelLocal
Published acreage0.9
Exact answer boundaryThis confirms the named federal record only.
It does not prove that another address lies inside this property or district, establish local landmark status, decide preservation review, define a legal boundary, or describe ownership or current condition.
Why the wording is date-boundedThe answer reflects the NPS dataset published through May 22, 2026 and a live NPS GIS Listed-status cross-check made September 20, 2026. NPS notes that spatial points and polygons may need correction and are not legal documents.
Additional published fields
Areas of significance: INDUSTRY, COMMERCE, POLITICS/GOVERNMENT, ARCHITECTURE.
Same locality
Other released Alton records.
Each linked page answers a separate named federal record.