United States. An American Consular Service Envelope, from the Franklin Roosevelt Collection, 1934

A white paper envelope with pre printed address THE HONOURABLE THE SECRETARY OF STATE, Washington, D.C. United States of America., with return address in the top left corner stating AMERICAN CONSUL SERVICE. and stamped Canton, China, the envelope has been stamped with a date mark 8. 5. 34. CANTON, with two additional stamps over the postage, numbered #496 inked in the bottom left corner, the reverse has three wax seals of the AMERICAN CONSUL GENERAL  CANTON CHINA, each one mostly intact, with ink stamp FROM THE FRANKLIN D. ROOSEVELT COLLECTION AUTHENTICATION BY H.R. INC. N.Y. The envelope is set into a clear plastic display, allowing both sides to be seen, measures 295 mm (w) x 138 mm (h) x 15 mm (d). The envelope bears discolouration, creasing, and a tear across the top. The containing case has small scratches and small chips to edges, remains in very fine condition. 

Footnote: The Franklin D. Roosevelt Collection includes American Consular Service envelopes from China, used for official mail often sent to the Secretary of State, featuring Chinese postage, red registration labels, and unique FDR collection authentication stamps (like H.R. Harmer) and wax seals, highlighting rare postal history from that era. These covers were part of FDR's significant stamp collection, started by his mother, and are prized by philatelists for their historical context and unique markings.

With the occupation of China occurring by the Japanese, actual mail correspondences is exceptionally rare. The Second World War in China was the single most wrenching event in modern Chinese history. The conflict is often termed the second Sino-Japanese War, and known in China as the War of Resistance to Japan. There are arguments that the conflict began with the invasion of Manchuria in 1931, but between 1937 and 1945, China and Japan were at total war. When Japan was finally defeated in 1945, China was on the winning side, but lay devastated, having suffered some 15 million deaths, massive destruction of industrial infrastructure and agricultural production, and the shattering of the tentative modernization begun by the Nationalist government.