It arrived at his Northern Virginia home last month.
McMurry told WTTG-TV/FOX5 he has "no idea" how the postcard, sent from Chicago's Shedd Aquarium, became lost for all these years, before being delivered to him in a large white envelope by a Virginia postmaster.
"I was just very pleasantly surprised," McMurry told the television station. "I can't say I was overwhelmed with emotion. I was just very pleasantly surprised. I was glad to have it."
"We'll probably be home before this gets there!" the postcard reads. "We are having a real good time. Hope you are all right."
WJLA-TV/ABC7 reports that the post office hasn't yet explained why the postcard took more than half a century to reach its intended recipient.
McMurry, a retired historian, told Fox5 he plans to frame the postcard. He's also planning to visit the Shedd Aquarium, which ABC7 reports has offered to give McMurry special tour.