The Framers of the Constitution and of the Bill of Rights revered trial by jury—a right that Sir William Blackstone had described as “the palladium of English liberty.” By the time of the Framing, common law juries had a more than five-century history in England, and they had been part of the American experience from the start. Although juries then were considerably less representative of the adult population than they are today, they were the most democratic of the governmental institutions in the colonies. Most Americans cheered their resistance to repressive colonial measures, especially British revenue laws and seditious libel laws.

In some colonies, juries had the power to judge questions of law as well as fact. They consisted of twelve people who always acted by unanimous vote. In felony cases, nonjury trials were unknown and guilty pleas infrequent. Trials were expeditious and routine.

The period since the Framing has seen notable changes in the general understanding of the right to jury trial.

As originally understood, the Sixth Amendment guaranteed the right to jury trial only in the federal courts, although each of the states also guaranteed trial by jury. The ratification of the Fourteenth Amendment in 1868 did not alter this understanding. One hundred years after the approval of the Fourteenth Amendment, however, the Supreme Court held in Duncan v. Louisiana (1968) that the amendment’s Due Process Clause “incorporated” the right to jury trial and made it applicable to the states. The Court said that although juries were not essential to fairness in every legal system, they were essential to the U.S. system. It wrote, “Providing an accused with the right to be tried by a jury of his peers gave him an inestimable safeguard against the corrupt or overzealous prosecutor and against the compliant, biased, or eccentric judge.”

The federal courts initially followed the jury selection rules of the states in which they sat, and all of the states limited jury service to men. All except Vermont also limited jury service to property owners or taxpayers. Only a few states formally disqualified blacks.

The Sixth Amendment was not thought to preclude the expansion of the right to serve on juries, but neither was it thought to require any expansion. Moreover, the Fourteenth Amendment’s Equal Protection Clause was not initially thought to extend “political” rights, including the right to serve on juries, to either African-Americans or women.

In 1880, however, the Supreme Court held in Strauder v. West Virginia that a statute disqualifying blacks from jury service violated the equal protection rights of black litigants. It was only in 1991 that the Court concluded that the Equal Protection Clause protected prospective jurors themselves from discrimination.

The Court has read the Sixth Amendment as well as the Equal Protection Clause to eliminate jury disqualifications of the sort the Framers approved. It held in 1975 that a “fair cross-section requirement” implicit in the amendment precluded the “systematic” exclusion of a “distinctive group in the community.” Because “systematic” exclusion need not be purposeful, the Sixth Amendment prohibits some forms of exclusion the Equal Protection Clause does not reach. Racial minorities and women qualify as “distinctive groups,” and under the Sixth Amendment, the exclusion of a distinctive group need not be purposeful and need not be total; it must merely be regular and foreseeable.

At the time of the Framing, litigants could challenge a limited number of prospective jurors peremptorily. In a series of cases beginning in 1986, however, the Court held that litigants may not use peremptory challenges to discriminate on the basis of race, sex, or any other classification subject to heightened scrutiny.

Although the Supreme Court previously had said that the Sixth Amendment required juries of twelve (a number that had more than half a millennium of history behind it), the Court concluded in 1970 that the amendment allows juries of six. In 1978, however, it held five-person juries impermissible. A great many states now use six-person juries, especially in misdemeanor cases.

In Apodaca v. Oregon in 1972, four Supreme Court justices concluded that conviction by a vote of ten to two did not violate the Sixth Amendment. Four justices dissented, arguing that the amendment preserved the historical requirement of unanimity. The remaining justice agreed with the dissenters on the construction of the Sixth Amendment but rejected the view that “all of the elements of jury trial within the meaning of the Sixth Amendment are necessarily embodied in or incorporated into the Due Process Clause of the Fourteenth.” As a result, non-unanimous verdicts are permissible in state but not federal courts. In a companion case, the Court upheld a state court conviction by a jury vote of nine to three. Later, the Court held conviction by a vote of five to one unconstitutional; convictions by six-person juries must be unanimous.

Although juries sometimes disregarded the legal instructions of judges in England, they never acquired formal authority to do so. As early as 1628, Chief Justice Edward Coke declared that judges do not decide questions of fact and juries do not decide issues of law.

The American practice, however, was different. In 1735 in New York, Andrew Hamilton told the court trying his client, publisher John Peter Zenger, that the authority of juries “to determine both the law and the fact” was “beyond all dispute.” The jury’s acquittal of Zenger, despite his apparent guilt of seditious libel, helped shape the American understanding of the role and duties of jurors. Some, but not all, American colonies permitted juries to decide issues of law, and in 1771 John Adams called it “an Absurdity to suppose that the Law would oblige [jurors] to find a Verdict according to the Direction of the Court, against their own Opinion, Judgment, and Conscience.”

The authority of juries to decide issues of law was contested throughout the nineteenth century, but the opponents of jury authority gained the clear upper hand in the century’s second half. Although three state constitutions still declare that juries may decide legal issues, the Supreme Court’s 1895 decision in Sparf and Hansen v. United States effectively ended the battle and held that federal juries may not decide questions of law.

In the late 1960s and early 1970s, defendants charged with unlawful resistance to the war in Vietnam sought to revive the issue. They argued that judges should inform jurors of their right to acquit whenever conviction would be unjust (or at least permit defense attorneys to argue in favor of jury nullification). Although appellate courts rejected the defendants’ arguments, the courts did not deny in all circumstances the appropriateness of jury nullification. If, as a matter of conscience, jurors decided to disregard the court’s instruction, their disobedience might be justified. More recently, however, many courts have denied the legitimacy of nullification altogether. Several have held that, even after jury deliberations have begun, a trial judge may remove a juror who has revealed “beyond doubt” an intention to violate the court’s instructions on the law.

The Anti-Federalists who opposed ratification of the Constitution protested that the right to jury trial guaranteed by Article III was inadequate. Their objections led to the Sixth Amendment’s requirement that juries must be drawn from “the State and district wherein the crime shall have been committed.” Although the Sixth Amendment also declared that juries must be impartial, the requirement of impartiality did not imply that jurors should arrive at the courtroom unaware of the circumstances of the case before them. George Mason and Patrick Henry insisted that local juries would protect the defendant’s right to be judged on the basis of “his character and reputation.” Courts now voice greater concern about information obtained prior to trial, especially in cases of widespread pre-trial publicity. The Supreme Court has said that although a juror need not “be totally ignorant of the facts and issues,” he must be able to “lay aside his impression or opinion and render a verdict based on the evidence presented in court.” Irvin v. Dowd (1961).

Since the Framing, a defendant has been entitled to a jury determination of every fact necessary to constitute the crime with which he has been charged. When finding a particular element would make the defendant guilty of a more serious crime rather than a lesser one, the effect was to increase his punishment. A defendant found guilty of murder, for example, was punished more severely than one found guilty of manslaughter.

In 2000, the Supreme Court held that a defendant is entitled to a jury determination of every fact necessary to increase the punishment to which he is exposed even when this fact is not formally called an element of a crime. Although a legislature might have called such a fact a sentencing aggravator, the Court concluded that it was functionally an element. Apprendi v. New Jersey (2000). Apprendi requires a jury to determine beyond a reasonable doubt every fact other than conviction of a prior offense that increases the maximum sentence a defendant faces. At the same time, the Supreme Court has said that the Apprendi principle does not require a jury to determine every fact necessary to impose a mandatory minimum sentence. In 2013, the Supreme Court decided that under the Sixth Amendment, any fact that increases the mandatory sentence is an “element” that must be submitted to the jury. Alleyne v. United States (2013).

The Supreme Court has applied Apprendi in a number of subsequent cases—notably in United States v. Booker (2005), which held mandatory federal sentencing guidelines unconstitutional.Under these guidelines, a judicial determination of fact automatically increased the sentence to which a defendant was exposed.

There were two majority opinions in Booker—one holding the guidelines unconstitutional and the other prescribing the remedy for this violation. Both majority opinions were by five to four votes, and only one justice joined both of them. The remedy approved by the Court was not to require a jury determination of every fact that would increase the maximum guideline sentence. It was to make the federal sentencing guidelines advisory. In other words, the Court’s remedy for a violation of the right to jury trial did not provide jury trials.

Every justice recognized, however, that discretionary sentencing by judges is constitutional, and the majority reasoned that Congress would have preferred advisory guidelines to guidelines administered by juries. In fact, discretionary sentencing was familiar to the Framers. The Crimes Act of 1790, for example, authorized judges to impose such punishments as maximum imprisonment of one, three, or seven years, or death, depending on the crime; a fine of up to “one thousand dollars,” and public whipping “not exceeding thirty-nine stripes.” It was only when finding a material fact automatically increased the punishment to which a defendant was exposed that the Sixth Amendment entrusted this finding to a jury.

At the time of the Sixth Amendment, all trials in serious criminal cases were jury trials. In 1874, the Supreme Court declared that a defendant could not “be tried in any other manner than by a jury of twelve men, although he consent in open court to be tried by a jury of eleven men.” Home Insurance Co. of New York v. Morse (1874). Nevertheless, the Court held in Patton v. United States (1930) that a defendant could waive the right to jury trial and agree to be tried by the court alone.

Today about half of all convictions in the felony cases that are resolved by trials occur in trials without juries. Moreover, only a small minority of felony cases go to trial. Ninety-seven percent of the felony convictions in federal courts and 94 percent of those in state courts are by guilty plea. Behind these figures lies the practice of bargaining with defendants to waive the Sixth Amendment right to jury trial.

Far from encouraging guilty pleas in felony cases, courts at the time of the Bill of Rights actively discouraged them. Sir William Blackstone’s Commentaries on the Laws of England (1765–1769) observed that courts were “very backward in receiving and recording [a guilty plea] . . . and will generally advise the prisoner to retract it.” Similar statements appeared in American treatises throughout the nineteenth century. When instances of plea bargaining began to appear in appellate reports in the decades following the Civil War, lower courts generally denounced the practice and often declared it unconstitutional. The Supreme Court did not uphold the constitutionality of plea-bargained waivers of the right to jury trial until 1970.

When jury trial was routine, it was a reasonably summary procedure. As recently as the 1890s, a felony court apparently could conduct a half-dozen jury trials in a single day. The intervening decades have seen a proliferation of procedures in contested cases and, as a result, an inability to contest many cases. Prolonged jury-selection procedures, cumbersome rules of evidence, repetitive cross-examination of witnesses, courtroom battles of experts, jury instructions that many empirical studies tell us jurors do not understand, and other complications have made trials inaccessible for all but a small minority of defendants. Only a shadow of the communitarian institution the Framers wished to preserve has survived into the twenty-first century. Although the Sixth Amendment declares, “In all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial, by an impartial jury,” one commentator has said that Americans could replace the word “all” in this Amendment with the words “virtually none.”