When did japan change the name of manchuria to manchukuo?

March of 1932. The Japanese invasion of Manchuria began on 19 September 1931, when the Kwantung Army of the Empire of Japan invaded Manchuria immediately following the Mukden Incident. After the war, the Japanese established the puppet state of Manchukuo. Their occupation lasted until the Soviet Union and Mongolia launched the Manchurian Strategic Offensive Operation in 1945.

c. had saved colonel cresap's family from attack by other native americans.