The following are a list of major historical events for INB, including mergers and acquisitions.
|1905-01-01||Institution established: Original name:The First National Bank of Fairmount|
|1999-06-21||Changed name to Illinois National Bank|
|1999-08-31||Change trust powers from TRUST POWERS NOT GRANTED to FULL TRUST POWERS GRANTED|
|2000-06-01||Moved bank headquarters from FAIRMOUNT, IL to SPRINGFIELD, IL|
|2004-10-29||Acquired Riverton Community Bank (19438) in RIVERTON, IL|
|2019-10-01||Changed name to INB, National Association|