In his State of the Union address, President James Buchanan complains that Arizona is “practically destitute of government, of laws, or of any regular administration of justice. Murder, rapine, and other crimes are committed with impunity.” President Buchanan urges Congress to establish a territorial government for Arizona.

President Abraham Lincoln signs the Arizona Organic Act, which creates the Territory of Arizona and abolishes slavery within its boundaries. Few, if any, slaves, however, were in the Arizona territory; the 1860 census identified twenty-four slaves (out of a total population of 93,541) in all of what is now Arizona and New Mexico.

Arizona’s Constitution is approved by Arizona voters. The Constitution reflects the early twentieth century Progressive Movement in American politics. This influence is shown by the Constitution’s protections of individual rights and its provisions providing for voter initiative and referendum, recall of elected officials, public utility regulation, establishment of a strong public-school system, and protection of the rights of workers and the right to sue for personal injury.

Statehood is delayed, however, by a provision in the proposed constitution allowing the recall of judges. President Taft vetoes statehood because of this provision. Arizona’s voters in 1911 approve a revised constitution omitting judicial recall, and Taft agrees to approve statehood.

Women win the right to vote through an initiative measure. Arizona is one of fifteen states granting women the right to vote before suffrage is obtained nationally in 1920.

The official 1916 election results give Republican Thomas Campbell the victory by thirty votes over incumbent governor George W. P. Hunt, a Democrat who has held office since statehood. Hunt contests the election but loses in the trial court. On Christmas Eve, 1917, the Arizona Supreme Court, after reviewing numerous disputed ballots, rules that Hunt has won the election. Campbell surrenders the office and Hunt completes the term through 1918. Hunt v. Campbell, 19 Ariz. 254, 169 P. 596 (1917); Campbell v. Hunt, 18 Ariz. 442, 162 P. 882 (1917).

Campbell successfully runs for governor again in 1918 and 1920. He was the first native-born Arizonan to serve as governor.

Voters amend the state constitution to allow annual legislative sessions instead of sessions every other year.

Voters approve the Modern Courts Amendment to Article 6 of the Arizona Constitution. This amendment is the basis for the current structure of Arizona’s judicial branch. Among other things, it increased the number of Supreme Court justices from three to at least five, it authorized the creation of a court of appeals, it made the Supreme Court responsible for rulemaking and administrative oversight for all state courts, and it set a mandatory retirement age of 70 for judges on the superior court, the court of appeals, and the Supreme Court.

The Arizona Legislature establishes the Court of Appeals.

The U.S. Supreme Court holds that juveniles in delinquency proceedings are entitled to certain rights (such as the right to counsel) afforded adults in criminal trials. In re Gault, 387 U.S. 1 (1967). The decision affects juvenile proceedings in courts throughout the nation.

Voters approve term limits for state officers, limiting legislators to four consecutive two-year terms (but allowing legislators to serve in the other house of the legislature or to serve again after waiting for one term out of office) and limiting the governor and other executive branch officials to two four-year terms. Ariz. Const. Art. 4 Pt. 2 § 21; Ariz. Const. Art.5, § 1.

Voters approve an initiative amending the Arizona Constitution to prohibit the legislature from modifying voter-approved laws unless the modification “furthers the purposes” of the law and only if the legislature approves the change by a three-fourths majority. Ariz. Const. Art. 4, Pt. 1, § 1(6). The amendment was in reaction to the legislature’s amending a 1996 citizen-sponsored initiative related to punishment for possessing drugs.