Department of the Interior, return penalty envelope, appears to be for Census 1880, as imprinted at left side, unused (Image)

Est. 30

Wilkins-Ellsworth Trans-Arctic Submarine Expedition, New York to North Pole, 1931, violet cachet, mailed from New York, May 3, overprinted 'FROM', Registered from London, & franked with British stamps, addr to Augusta, Maine, BS London 19 Oct, Boston & New York Oct 28 (Image)

Est. 40

1932 Washington Bi-Centennial Celebration, 34 covers, mixed cachets, addr

Est. 35

1937-38, set of three covers for the 200th Anniv of the Surrender of Yorktown, two covers with a single stamp, each with a different cachet on different colored cover, VF (Image)

Est. 15