After Heller, a major constitutional question remained: could states and cities be held to the same individual-right rule?
Chicago handgun restrictions triggered the case
Residents challenged Chicago-area firearm restrictions after Heller invalidated the D.C. handgun ban.
The Court incorporated the Second Amendment
A majority concluded that the right recognized in Heller applies against the states through the Fourteenth Amendment.
Reconstruction history became central
The opinions examined post-Civil War civil-rights history, including concerns about disarming freed people and the meaning of the Fourteenth Amendment.
State gun laws became subject to federal constitutional review
McDonald opened the door to constitutional challenges against state and local firearm regulations that previously could not be tested under an incorporated Second Amendment right.
Where this fits in the larger timeline
This event is part of the History of Gun Laws in America series. Federal firearm law developed incrementally through constitutional amendments, taxation and commerce statutes, criminal prohibitions, background-check legislation and modern Second Amendment decisions.