1933/36, United States, “century Of Progress” Issue

50 Cent. Green, Air Post (scott C18) On Fdc To Woodbury, N. J.; “first Flight Hindemburg”, 10 Cent. Dark Blue (2), 20 Cent. Yellow-green, 6 Cent. Dull-orange (scott C9, C10, C19) On Cover With Special Violet Handstamp. Backstamped “frankfurt (main) 14.5.34-8-9-b” Circular Date Stamp And “berlin C - 14.5.36” (siegel 409c).