The total prize money for the men's and women's para-athletic field has been increased to $134,500 from $98,500 last year and the marathon will serve as the United States Paralympic Team Trials for the second time.
The marathon benefits from its proximity to the University of Illinois at Urbana-Champaign, where some of the world's premier wheelchair athletes, including McFadden, have trained.
The American will be up against returning champion Manuela Schar of Switzerland, who has enjoyed a dream stretch of results, winning in New York, Tokyo, Boston and London.
American Dan Romanchuk, who won here last year at the age of 20 and became the youngest athlete to win the New York Marathon a month later, is among the favorites on the men's side.
With another year's experience in competition, Romanchuk said he had improved his racing strategy.
"I know my limits more than I did," said Romanchuk. "I think training has been going well. I don’t like to make any assumptions about any race. We’ll see."
Chicago race director Carey Pinkowski said he was impressed by Romanchuk's physical prowess and strength.
"If you listen to the guys at University of Illinois about what he does in training, how intense he is -– he’s a young guy but he’s just strong, he’s come storming on," Pinkowski said. "I think he’s going to be the guy for a long time." (Reporting ; editing by Clare Fallon)