FamilySearch is currently indexing the 1905 Iowa State Census and more Iowa County Marriages, 1838-1992. Many entries look very much alike, but each one comes from a different document or document page.
The Missouri State Archives is working on an online database that will include over 3 million Missouri marriages from the territorial period through 1969. They will be linking to the records on familysearch.org initially, but eventually these will be a part of the Missouri Digital Heritage website hosted by the Secretary of State’s office. If you search for “Missouri State Archives,” you will see the progress of this project. Nearly 200,000 marriages had been completed by June 2013.