One morning at the Atlantic City Country Club where he was a professional, McDermott blacked out and was found unconscious. He apparently suffered a nervous breakdown. After that, he was institutionalized and spent the rest of his life living either with his sister in Philadelphia or in local mental institutions. He did play on occasion, however, with Tim DeBaufre at Valley Forge and others, until his clubs were stolen from his sister’s car.
One club survived. While playing with a stranger, he borrowed a club from his playing companion, liked it, and was allowed to keep it. In return, he gave up an old wooden mashie, saying to his incredulous playing partner, “That club helped me win two U.S. Open championships.”
Besides his sisters, Gertrude and Alice, Atlantic City Country Club owner Leo Fraser also made sure McDermott was taken care of in his later years. Fraser invited him to visit the club and named the McDermott Room after him. In return, McDermott’s sisters gave Fraser one of his U.S. Open championship medals, valued at $40,000, which the Fraser family donated to the USGA, and is now on display at the USGA museum in Far Hills, New Jersey.
When the 1971 U.S. Open was held in Philadelphia at the Merion Country Club, McDermott’s sister left him alone in the clubhouse where a young assistant pro, Bill Pappa, thought John was in the way and ordered him out of the pro shop.
As it was later reported, “In 1971, Arnold Palmer, while playing the U.S. Open at Merion Golf Club, noticed a shambling old man being ejected from the lobby. Palmer recognized him as John McDermott who, in 1911, had been the first American to win the U.S. Open." Tossing out such a man wouldn’t do, decided Palmer, who shooed away club employees and escorted McDermott back inside. “They talked golfer to golfer, champion to champion,” wrote golf historian John Coyne, “and Palmer then arranged for McDermott to stay at the tournament as his special guest.”
Two months later McDermott died in his sleep at his sister’s home in Philadelphia.