The medallion's obverse bears sailor in heavy gear at helm of ship. Around, MARINE NATIONAL EXCHANGE BANK OF MILWAUKEE / 100TH ANNIVERSARY; signed to left of sailor, (JFP monogram)
The reverse bears legend within wreath. At top, 1839 - 1939; below, WISCONSIN / MARINE & FIRE / INSURANCE CO. / 1839 / MARINE NATIONAL / BANK / 1900 / BANK / OF / MILWAUKEE / 1855 / NATIONAL EXCHNQNGE / BANK / 1865 / CONSOLIDATED AS / MARINE NATIONAL / EXCHANGE BANK / of MILWAUKEE / 1930
The Marine National Exchange Bank of Milwaukee was formed in 1930 through the merger of four different companies, the oldest of which traced its roots back to 1839. While I am totally speculating, I assume that the merger was a necessity rather than a choice. The Great Depression had just started a year earlier and many financial institutions had come under intense pressure to consolidate or go bankrupt. The Marine National Exchange Bank was finally taken over by Bank One in 1988, not quite making it to its 150th anniversary as an independent entity.
The circular medallion measures 82.4mm in diameter and was struck in bronze by the Whitehead & Hoag Company of Newark, New Jersey.