Lot of 77 U.S. First Day Covers from 1970–1979, most with original USPS inserts, letters or brochures explaining the stamp issue and historical event. 67 of the 77 include the full documentation, while 10 are missing inserts. Covers are in excellent shape, having been carefully stored together in a plastic sleeve by the original collector. A well-preserved postal history set perfect for stamp collectors and enthusiasts of 1970s Americana.