I'm a member of the United States Stamp Society. One of the most important benefits of being a member is receiving their monthly journal The United States Specialist. It is a wonderful source of philatelic information about postage stamps of the United States. The August issue for 2022 contained an especially interesting and informative article by Jay Stotts titled "One Collector's Fourth Bureau Issue Top Ten List". The Fourth Bureau set of stamps was first issued in 1922 and continued until 1938. Among Stotts' top ten list of these stamps were two that were of special interest to me. The first was the 11 cent Rutherford B. Hayes stamp which was issued by the United States Post Office Department (USPOD) on October 4, 1922. A special First Day of Issue ceremony was held for the stamp in Fremont, Ohio, the location of the Rutherford B. Hayes Presidential Library. First day covers were processed with the Hayes stamp and canceled with a Fremont, Ohio, October 4, 1922 cancel. One of those covers is shown above. The image is provided with the courtesy of Jay Stotts. According to Stotts this began the practice of holding first day of issue ceremonies and mailing first day covers at the site of the ceremony which continues to this date. I collect postal artifacts related to America's presidential libraries and have shown an exhibit of those items at several stamp shows. Jay told me that in his opinion the Fremont first day ceremony at the Hayes Library was in his eyes, a key philatelic event involving a presidential library. Which makes the Hayes first day cover a highly desirable item for my exhibit. If only I could afford one.
Jerry Katz has a fantastic site on the FDCs of the 11¢ Hayes Postage Stamp of 1922.
The second item in Jay's top ten list of particular interest to me is a first day cover featuring the 1923 2 cent Warren G. Harding stamp which was issued by the USPOD on September 1, 1923. This cover is considered to be America's first cacheted first day cover. It was produced by George W. Linn, the founder of Linn's Stamp News. A cachet in philately is any kind of illustration or printed information on a cover (envelope) that is not related to the cancellation, postmark, or address. The cachet on Linn's first day cover includes printed information about Harding. The cover is also a mourning cover. An example of the cover is shown below.