USA Proof of the 1875 official reprint of the first issue affixed on a thick board (Image1)

USA 1893 Columbian Expo. 1c-50c used catalog value:52,000YEN (Image1)

USA Air Post Stamp 1918 6c single franking First Class Mail cancelled by Duplex 1920-03-11 NEW YORK to Los Angeles transit :SANFRANCISCO 1920-03-17 (Image1)

USA , 2 covers Air Post Stamp 1918 24c single franking cancelled by Duplex 1924-07-02 CH(ICAG)O letter, airmail , (Image1)

USA , 2 covers Air Post Stamp 1918 8c single franking cancelled by Duplex 1919-05-07 MACON (Image1)

USA , 2 covers Air Post Stamp 1918 16c cancelled by Duplex 1918 AIRMAIL SERVICE WASH. N.Y. PHILA. NEW YORK (Image1)

USA Air Post Stamp 1918 24c , 2 covers single franking cancelled by Duplex in purple 1918-06-14 AIRMAIL SERVICE WASH. N.Y. PHILA. NEW YORK、 arrival :（印影一部欠け） airmail , (Image1)

USA 1918 24c , 2 covers single franking stained, 1918-05-31 PHILADELPHIA arrival :WASHINGTON (Image1)

USA , 2 covers Air Post Stamp 1923 16c single franking stained, cancelled by Duplex 1924-08-24 CHICAGO arrival :SANFURANCISCO (Image1)

USA , 2 covers Air Post Stamp 1923 24c single franking cancelled by Duplex 1926-08-24 SAN FRANCISCO arrival :NEW YORK (Image1)

USA 1924-1926, 3 covers Air Post Stamp 1923 24c BROOKLIN, SAN FRANCISCO, NEWAR( ), letter, airmail , (Image1)

USA Special Delivery Stamp, Air Post Stamp, 1938-1942, 9 covers single franking Multi-color franking cancelled by Duplex machine cancellation airmail , (Image1)

USA 1928-1932, 8 covers single franking Multi-color franking and etc cancelled by Duplex machine cancellation letter, airmail , (Image1)

USA 1926-1928, 5 covers single franking Multi-color franking and etc cancelled by Duplex machine cancellation airmail , (Image1)

USA Multi-color franking cancelled by Duplex machine cancellation NEWARK, PASADENA, PHILADELPHIA, SAN FRANCISCO, 1924-1926, 5 covers airmail , cover stained, torn cover, (Image1)

USA , 3 covers Ships Mail to Coast cancelled by Duplex 1941-03-27 HONOLULU HAWAII to South Carolina and two more covers (Image1)

USA , 1 covers, 1post(al) cards 1910-12 2c single franking cancelled by datestamp in purple 1912-08-23 VIA AREOPLAIN MAIL BOOT (Image1)

USA 1920-1021, 4 covers single franking cancelled by Duplex machine cancellation AIROPLAINSTATION No.1, MINEAPOLIS, CHICAGO,ほか airmail , (Image1)

USA 1924-1926, 3 covers Air Post Stamp 1923 8c 16c, Special Delivery Stamp 10c, single franking cancelled by Duplex machine cancellation LOS ANGELS, ATCHISON, airmail , cover stained, (Image1)

USA 1932-1944, 10 covers, 1post(al) cards single franking Multi-color franking and etc cancelled by Duplex machine cancellation airmail , (Image1)

USA Air Post Stamp, Special Delivery Stamp, 1928-1932, 5 covers, 1post(al) cards single franking Multi-color franking cancelled by Duplex machine cancellation letter, airmail , (Image1)

USA 1927-1928, 7 covers single franking Multi-color franking and etc cancelled by Duplex letter, airmail , (Image1)

USA 1922-1925, 4 covers single franking cancelled by datestamp Duplex machine cancellation AEROPLAINSTATION, AIR MAIL SERVICE, SAN FRANCISCO, SPRINGFIELD, airmail , (Image1)

USA Air Post Stamp 1926-27 15c 20c, 1927 10c, 1927-1928, 3 covers, 1post(al) cards single franking cancelled by Duplex machine cancellation ASH 84 SANFRAN.R.P.O., PEORIA, WASHINGTON, , WASHINGTON D.C., airmail , (Image1)

USA 1893-1986104leaves mixed condition of unused and used, (Image1)