The man in "American Gothic" wasn't a farmer at all — he was Grant Wood's dentist, Byron McKeeby. Wood admired McKeeby's strong hands and thought he would make the perfect model for the painting he had in mind. McKeeby initially declined, but he may have felt obligated to do it because Wood's love of sugar made him a frequent patient (via Mental Floss).
Wood promised to exaggerate McKeeby's features in the painting so he wouldn't be recognizable, but that didn't work out. As the painting became more and more famous, many people recognized McKeeby and asked him about it. He denied being the model for years, until finally admitted it in 1935. Later, in 1943, he actually went on a radio broadcast to talk about the painting. He said that his notoriety had slightly strained his friendship with Wood, but that no one could stay mad at Wood for long (via The Gazette).
Unlike in the painting, McKeeby was known to have a good sense of humor and stylish clothes. Interestingly, his grandson and namesake went on to be an artist himself.
