June 24 is the Illinois petition deadline for independent candidates, and for nominees of unqualified parties. The Green, Libertarian, and Constitution Parties submitted petitions, as did independent presidential candidate Robert F. Kennedy, Jr.
The Illinois petition deadline had been in August until 1999, when it was moved to June. Illinois has one of the earliest petition deadlines for general election presidential candidates of any state. In 2000 a U.S. .District Court enjoined the deadline in a case filed by Ralph Nader, but no declarative relief was sought or granted. So the June deadline continues to exist in the law.