The man on the left in the photo is Dr. Richard Hornberger (aka Richard Hooker), who wrote the original M*A*S*H novel in 1968. The man on the right was one of Dr. Hornberger’s tent mates, Dr. Agrippa (“Grip”) Kellum that signed the photo. Another tent mate not pictured here was Capt. Michael Johnson, the basis for the character Trapper John. The picture is from the 8055th Mobile Army Surgical Hospital in 1952, South Korea (the novel, movie, and TV series had it renamed the 4077th).
That was the real ‘Swamp’ tent that was portrayed in the film and TV series. Another interesting thing to note is the symbol on the front door, which is an ancient Moorish symbol meant to bring good luck and ward off evil.
The character of Capt. Benjamin Franklin ‘Hawkeye’ Pierce was based on Hornberger and the novel loosely followed some of his experiences as a doctor working in a M*A*S*H unit during the Korean War.
While Dr. Hornberger loved the 1970 movie adaptation of his novel, he hated the TV series as he was more conservative and the TV version of Hawkeye was more liberal. He of course didn’t complain too much as he was laughing all the way to the bank. Richard Hornberger passed away from complications of leukemia at the age of 73 on November 4th in 1997.