Professor Graff quoted General George C. Marshall as saying “that message was worth 25,000 men’s lives.”

“I, a kid, would come in and look to see if we had any messages from Oshima to the Japanese Foreign Office,” he recalled. “And I was reading messages that reported his conversation with Hitler the day before. I cannot tell you other than I felt that I was at the center of the universe.”

Nine months later, he translated another intercepted message, this one from Japan to the Soviet Union.

“I was the first American, the first member of the Allied side, to know Japan was going to get out of the War,” he said, “because I was working at two in the morning in 1945 shortly after Hiroshima, and I got this message asking Bern, Switzerland, to help get them out of the war.”

If Japan had not surrendered, Professor Graff was expected to be deployed with the Allied invasion forces.

Henry Franklin Graff was born on Aug. 11, 1921, in Manhattan to Samuel F. Graff, a salesman in the Garment District, and Florence (Morris) Graff, both descendants of Jewish immigrants from Germany. His maternal grandmother’s family had a clothing store in East Harlem.

Raised in the Inwood section of Manhattan, he graduated from George Washington High School at 16 and earned his bachelor of social science degree from City College in 1941. He was working toward his master’s at Columbia (“I was the first Jew in the Columbia History Department,” he said) when he enlisted. After the war, he taught history at City College before joining the Columbia faculty in 1946 and earning his doctorate in 1949.