1937 China Clipper First Flight Cover U.S. to Canton, China via Macao

Striking airmail cover carried on the April 21, 1937 Pan Am China Clipper flight from San Francisco to Canton, China. Bold dual-cachet design in black and blue marks the inaugural transpacific route via Honolulu, Guam, Manila, and Macao. Addressed to Canton and backstamped at Hong Kong and Canton, with typed return address on reverse. A scarcer destination on this historic route.