Can of Corn (1926)

“When a pop fly falls over those short fences and beats them, it is the breaks and nothing else. They would be easy outs in a regular sized park—what is known by ball players as a ‘can of corn.’” H.B. (Duby) duBose. Austin American, August 7, 1926, p5

Previous earliest use (Dickson Baseball Dictionary, 3rd edition, 2009):
1ST USE. 1930. “[Jesse Hill] leaped up to turn what looked like a sure double into just a can of corn, as the baseball boys call an out.” (Los Angeles Times, June 19).