In 1957, the country celebrated the 150th anniversary of the U.S. Coast and Geodetic Survey (USC&GS) by printing stamps featuring the USC&GS flag and three ships.
An envelope with an image of U.S. Coast and Geodetic Survey (USC&GS) employees surveying, a USC&GS stamp, and a first day of issue cancelation. Many of these stamps and envelopes survive today, including some mailed across the country. (Addressee name and address have been blurred out for privacy.) (Image credit: NOAA Heritage)