(Politics) J. Edward Day (1914-1996), 55th U.S. Postmaster General, 1961-1963 under President John F. Kennedy. Under his tenure, two important events occurred: 1) Zip codes were introduced, making mail sorting and delivery more efficient, 2) The first intentional issue of an error stamp (the Dag Hammersjold invert) occurred. Signature on #1204 FDC of the Dag Hammersjold invert with Fleetwood cachet and neat typed address. Very iconic! (Image)

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