| Timeline |
| 1913 |
Sullivan sketches bank design while in Grinnell. November. View sketch. |
| 1914 |
Merchants National Bank built for $60,000 for staff of six to eight persons. |
| 1915 |
Doors opened for business (January 1). |
| 1924 |
Merchants National Bank closed, a victim of the agricultural depression of the 1920s. |
| 1926 |
Citizens National Bank purchased and occupied building. |
| 1930 |
June 16, Poweshiek County National Bank opened its doors to the public, as the Brenton family took over the Citizens National Bank. |
| 1956 |
First major remodeling project undertaken. Brooks-Borg, Des Moines architects. Air conditioning added. Wood paneling added to cover the west brick wall that had been painted white. |
| 1964 |
Minor changes made. |
| 1974 |
Architects Stewart-Robinson-Laffan of Davenport, Iowa, received commission for the 12,000 square foot addition, remodeling, and some restoration of the 3,200 square foot Sullivan building. Restoration included the lights on the check desk and clock over front doors. |
| 1976 |
Received designation of National Historic Landmark (January). |
| 1976 |
Work completed on 1974 addition. |
| 1984 |
Vandals shattered east Griffin. Restored by Architectural Terra Cotta & Tile Ltd. of Chicago. |
| 1985 |
Bank name changed to Brenton National Bank Poweshiek County. |
| 1992 |
West Griffin wing stolen and not recovered. |
| 1994 |
Restoration of Griffins by Kennedy Restoration Company, Mt. Carroll, Illinois. |
| 1999 |
Sullivan Bank is no longer used for banking. All remaining Brenton Bank staff moved into newly remodeled 1974 expansion. Sullivan Bank building leased to Grinnell Area Chamber of Commerce. |
| 2000 |
Wells Fargo Bank purchased Brenton Bank and the Sullivan Bank Building. |
| 2006 |
Vandals shattered east Griffin. |
