The postcard was sent July 4, 1943, from Rockford, Ill., to sisters Pauline and Theresa Leisenring in Elmira.
Their brother, George Leisenring, was stationed at Rockford's Medical Center Barracks at Camp Grant, an Army post during World War II. Their parents were visiting him when they mailed the postcard home.
The postcard reads in part, "Dear Pauline and Theresa, We arrived safe, had a good trip, but we were good and tired."
Elmira's Star-Gazette newspaper reports the postcard arrived last week at the family's former home, where a different family now lives.
A postal official says the postcard may have been found by someone outside the postal service and placed in the mail.