Whit's role is small but significant in Of Mice and Men. He is introduced one night in the bunkhouse when he shows a letter that's been printed in a pulp magazine to Slim. His effort to impress Slim and his desire to connect to a "celebrity," someone published in a magazine, shows readers that Lennie and George are not the only men with dreams... nor are they the only men whose dreams are being crushed by the weight of the migrant worker life.
Whit is described as a young man, but also one whose posture suggests that he has aged prematurely; he carries the weight of his life and job on him at all times.
A young laboring man came in. His sloping shoulders were bent forward and he walked heavily on his heels, as though he carried the invisible grain bag.
Readers learn that Whit is yet another character who sees Slim as a leader and as someone to admire. It's not a stretch to believe that Whit sees himself as someday possessing the same confidence and leadership as Slim. He shows Slim the magazine--only Slim--and when Slim doesn't make the connection to the name, Whit reminds him that William "Bill" Tenner was also a worker on the farm several months earlier. Through Whit, readers learn that Bill Tenner achieved one of his dreams--to have his letter published in his favorite magazine. Readers can also see a desire in Whit to connect, in however small a way, to Bill's success.
"That's him," Whit cried. "That's the guy!"
"You think he's the guy wrote this letter?"
"I know it. Bill and me was in here one day. Bill had one of them books that just come. He was lookin' in it and he says, 'I wrote a letter. Wonder if they put it in the book!' But it wasn't there. Bill says, 'Maybe they're savin' it for later.' An' that's just what they done. There it is."
He goes on to say that he was the one who primarily ran the cultivator with Bill.
"I wonder if Bill seen it," he said. "Bill and me worked in that patch of field peas. Run cultivators, both of us. Bill was a hell of a nice fella."
When George asks to see the letter, Whit will let him see it, but he doesn't allow George to hold the magazine as he did Slim. This particular detail illustrates that George and Lennie have not yet been fully accepted by the ranch hands, though Whit can't quite resist showing the letter to anyone who wants to see it.
Whit is an incredibly minor character, but he serves the larger purpose of illustrating the hopelessness with which George and Lennie are living. Unlike the older men like Slim and even Candy, Whit is a young man with a potential future; yet readers know that it's unlikely for Whit to ever be more than exactly what he already is: a worker already bent over with the weight of laboring for someone else's gain.