Helping to fill the seemingly endless appetite for information about World War II, the New-York Historical Society is planning a major exhibition on the conflict’s effect on the homefront this fall.

Titled “WWII & NYC,” the exhibition is scheduled to open Oct. 5 and run through May 27. Among the documents scheduled for display is a rare copy of the original Instrument of Surrender, Japan’s formal surrender to the Allies on Sept. 2, 1945, that will be exhibited starting on Sept. 21, before the rest of the exhibition opens. The document, one of 20 copies of the surrender agreement created at the time, has not been displayed in New York since 1945....