Stamp recognizes Colorado\u27s 75th anniversary of statehood 1876-1951. First day covers are envelopes or postcards with a stamp canceled on the first day the stamp is available for purchase and use. Often the postmark is a special pictorial cancellation indicating the city and date of issue. First day covers often include a cachet or illustration on the envelope that explains or compliments the stamp.https://digitalcommons.fairfield.edu/firstdaycover/1082/thumbnail.jp
