Most criminal prosecutions occur at a level that is both neglected by many legal scholars and central to the lives of most people entangled in the criminal legal system: the level of the state. State v. Citizen prosecutions, which encompass most crimes ranging from robbery to homicide, are governed both by the federal constitution and by the constitution of the prosecuting state.

This is no less true for sentences than for prosecutions. When it comes to sentences, state courts are bound by the Eighth Amendment to the United States Constitution, which famously proclaims that no American shall be subjected to “cruel and unusual punishment.” But state constitutions may go further than the federal constitution. States may adopt constitutional provisions analogous to the Eighth Amendment that establish even more effective guards against unreasonable or vindictive punishments.

One state—Illinois—has so chosen. At Illinois’s most recent constitutional convention in 1970, a group of statewide delegates agreed to reconsider the limits set by the state’s constitution on criminal punishments.

From that convention emerged a revolutionary idea: that Illinois should adopt in its constitution the strongest known language in the nation limiting a government’s ability to mete out extreme punishments to those citizens who have transgressed the criminal law—and clearly identifying the purpose of those criminal sentences as rehabilitation. Thus was born what appears in Illinois’s constitution today: the so-called proportionate-penalties clause. That clause, codified in 1970 as Article 1, Section 11 of the Illinois Constitution, proclaims that “all penalties shall be determined both according to the seriousness of the offense and with the objective of restoring the offender to useful citizenship. No conviction shall work corruption of blood or forfeiture of estate. No person shall be transported out of the State for an offense committed within the State.”

This Article traces the origins of the proportionate-penalties clause back to the 1970 constitutional convention, using floor debate transcripts and other contemporaneous sources to establish that its authors did, indeed, intend Illinois sentences to serve rehabilitative purposes. To interrogate the context of those documents, this Article also examines the surrounding historical events of late 1960s-era Chicago, as well the lives and identities of the delegates who propelled this clause forward.

This Article uses the authors’ words as prescient calls for a new interpretation of the proportionate-penalties clause that hews to their vision —and that can serve as a model for rethinking the guardrails around criminal punishments nationwide. Indeed, a constitutional scheme that insists that criminal penalties be directed at rehabilitative ends can and must carry implications for many of the statutes and rules that sustain our current system of mass incarceration.