Country: USA
Issue: 50th Anniversary of the Soo Locks – Great Lakes Transportation
Date of Issue: June 28, 1955
Postmark: First Day Cancellation – Sault Sainte Marie, Michigan – June 28, 1955
Postcard: Colored illustration showing the excursion boat Messenger passing through the Soo Locks alongside a giant freighter, with the caption: “Excursion Boat ‘Messenger’ Locking thru with Giant Freighter, Soo, Mich.”
Justification of Maximum Concordance:
Yvert & Tellier: US 596



















