“The National Register of Historic Places is the official list of the Nation’s historic places worthy of preservation. Authorized by the National Historic Preservation Act of 1966, the National Park Service’s National Register of Historic Places is part of a national program to coordinate and support public and private efforts to identify, evaluate, and protect America’s historic and archeological resources.”
In Missouri, the National Register of Historic Places is administered by the State Historic Preservation Office (a branch of the Department of Natural Resources under Missouri State Parks).
The State Historic Preservation Office has shared some useful presentations regarding the National Register and hiring consultants to complete National Register work.
The State and the Federal government do not issue plaques for buildings that are listed on the National Register.
However, building owners are free to do this and can order recognition plaques from a website like this one.