May 20th: President Barack Obama, whose home-state of Illinois, was the affected state, has offered to help the state of emergency called by Governor Bruce Rauner and mayor Rahm Emanuel, of chicago, calling on the U.S. National Guard, under the command of General Frank J. Grass, the 27th Chief of the National Guard Bureau, this action was allowed following the on going national emergency, declared after the September 11 attacks, authorizing the incumbent president the power to retain or reactivate military personnel beyond their normal term of service