He was 80-years-old and died after a long illness. From the Herald Tribune:

A retired maintenance worker who saw his Chicago neighborhood becoming overrun by gang members and drug dealers, McDonald’s desire to protect himself with a handgun eventually brought down the Chicago Gun Ban, which had been law in the Windy City since 1982.

In the landmark case McDonald v. City of Chicago, (2010), the Supreme Court ruled that the Second Amendment applies to the states. It means that Americans have a right to keep and bear arms regardless of their zip code.

More at the link.