Hollingsworth v. Perry refers to a series of United States federal court cases that legalized same-sex marriage in the State of California.
 The case began in 2009 in the U.S. District Court for the Northern District of California, which found that banning same-sex marriage violates equal protection under the law.
 This decision overturned ballot initiative Proposition 8, which had banned same-sex marriage.
 After the State of California refused to defend Proposition 8, the official sponsors of Proposition 8 intervened and appealed to the Supreme Court.
 The case was litigated during the governorships of both Arnold Schwarzenegger and Jerry Brown, and was thus known as Perry v. Schwarzenegger and Perry v. Brown, respectively.
 As "Hollingsworth v. Perry", it eventually reached the United States Supreme Court, which held that, in line with prior precedent, the official sponsors of a ballot initiative measure did not have Article III standing to appeal an adverse federal court ruling when the state refused to do so.
During the tenure of Morrison Waite as Chief Justice of the Supreme Court of the United States (March 4, 1874 through March 23, 1888), the Supreme Court heard an unprecedented volume and frequency of criminal cases.
 In just fourteen years, the Court heard 106 criminal cases, almost as many cases as the Supreme Court had heard in the period from its creation to the appointment of Waite as Chief Justice.
 Notable cases include "United States v. Cruikshank" (1875), "United States v. Reese" (1875), "Reynolds v. United States" (1878), "Wilkerson v. Utah" (1879), the "Trade-Mark Cases" (1879), "Strauder v. West Virginia" (1880), "Pace v. Alabama" (1883), "United States v. Harris" (1883), "Ex parte Crow Dog" (1883), "Hurtado v. California" (1884), "Clawson v. United States" (1885), "Yick Wo v. Hopkins" (1886), "United States v. Kagama" (1886), "Ker v. Illinois" (1886), and "Mugler v. Kansas" (1887).
The Marshall Court (1801–1835) heard forty-one criminal law cases, slightly more than one per year.
 Among such cases are "United States v. Simms" (1803), "United States v. More" (1805), "Ex parte Bollman" (1807), "United States v. Hudson" (1812), "Cohens v. Virginia" (1821), "United States v. Perez" (1824), "Worcester v. Georgia" (1832), and "United States v. Wilson" (1833).
United States v. Nixon, 418 U.S. 683 (1974), was a landmark United States Supreme Court decision which resulted in a unanimous 8–0 ruling against President Richard Nixon, ordering him to deliver presidential tape recordings and other subpoenaed materials to the District Court.
 Issued on July 24, 1974, the ruling was important to the late stages of the Watergate scandal, when there was an ongoing impeachment process against Richard Nixon.
 "United States v. Nixon" is considered a crucial precedent limiting the power of any U.S. president to claim executive privilege.
Stephen P. Halbrook is a Senior Fellow at the Independent Institute and an author and lawyer known for his litigation on behalf of the National Rifle Association.
 He has written extensively about the original meanings of the Second Amendment and the Fourteenth Amendment (the latter as applied to Second Amendment rights).
 He has argued and won three cases before the US Supreme Court: "Printz v. United States", "United States v. Thompson-Center Arms Company", and "Castillo v. United States".
 He has also written briefs in many other cases, including the Supreme Court cases "Small v. United States" (pertaining to the Gun Control Act of 1968) and "McDonald v. Chicago".
 In "District of Columbia v. Heller", he wrote a brief on behalf of the majority of both houses of Congress.
 More broadly, his decades of research on the Second Amendment contributed to the intellectual foundation of the "Heller" decision.
 He has written many books and articles on the topic of gun control, some of which have been cited in Supreme Court opinions ("Heller", "McDonald", "Printz v. United States").
 He has testified before congress on multiple occasions.
 Halbrook’s most important scholarly contribution, however, was the book "That Every Man Be Armed", originally published in 1986.
 The book was the most thorough analysis of the legal history and original intent of the Second Amendment.
United States v. Hamilton, 3 U.S. 17 (1795) , was a United States Supreme Court case in which a defendant committed on a charge of treason was released on bail, despite having been imprisoned upon a warrant of committal by a district court judge.
 The Judiciary Act of 1789 stated that "upon all arrests in criminal cases, bail shall be admitted, except where the punishment may be death, in which cases it shall not be admitted but by the supreme or a circuit court, or by a justice of the supreme court, or a judge of a district court, who shall exercise their discretion therein, regarding the nature and circumstances of the offence, and of the evidence, and the usages of law."
 Ordinarily, habeas corpus was used to release prisoners held by the judgment of the executive, but not for those who commitment had been authorized by a court order.
 Hamilton's attorney argued that the district court judge did not hold a hearing before issuing a warrant for his commitment to jail and that the affidavits alleging treasonous activity were weak, while the government urged that the Judiciary Act did not give the Supreme Court the jurisdiction to review the district court's decision unless there was new information or misconduct.
 The Supreme Court set bail, but without addressing either attorney's arguments.
United States v. Barker, 15 U.S. 395 (1817), was a case decided by the United States Supreme Court upholding the common law tradition that private citizens may not demand costs from the federal government.
 The case involved a motion for costs filed against the United States Government and resolved the previously unanswered question of whether courts could award costs against the United States federal government.
 The Court's opinion read, in its entirety, "[t]he United States never pay costs."
 Jurists have remarked that Chief Justice John Marshall's six-word opinion is one of the shortest Supreme Court cases ever written.
On April 28, 2015, the Supreme Court of the United States heard oral arguments for "Obergefell v. Hodges" (Ohio), which was consolidated with three other same-sex marriage cases from the other states in the Sixth Circuit: "Tanco v. Haslam" (Tennessee), "DeBoer v. Snyder" (Michigan), "Bourke v. Beshear" (Kentucky).
 On June 26, 2015 the Supreme Court reversed the Sixth Circuit's decision, paving the way for same-sex marriage to become legal in those states, and setting a precedent for the entire nation.
 All four states complied with the ruling the same day it was issued before the mandate was actually issued.
 Every state in the circuit had a district court ruling against their states' ban, but they were eventually stayed pending appeal.
 The Sixth Circuit consists of Kentucky, Michigan, Ohio, and Tennessee.
 On August 6, 2014, the Sixth Circuit heard oral arguments for same-sex marriage cases from each state within the circuit.
 On November 6, 2014, the Sixth Circuit in a split 2-1 decision, upheld the states' same-sex marriage bans, reversing the district courts' rulings that struck them down.
 The Sixth Circuit was the first and only circuit court since the landmark ruling "United States v. Windsor" to uphold the constitutionality of states' same-sex marriage bans which caused a circuit split.
Zelman v. Simmons-Harris, 536 U.S. 639 (2002) , was a 5-4 decision of the United States Supreme Court that upheld an Ohio program that used school vouchers.
 The Court decided that the program did not violate the Establishment Clause of the First Amendment even if the vouchers could be used for private, religious schools.
Evans v. Jordan, 13 U.S. 199 (1815) , was a United States Supreme Court case in which the Court held that someone who had copied a patented invention after the patent had expired, and before the patent was restored by a private bill, would be liable for damages for patent infringement for any use continuing after the patent was restored.
 It was the second published Supreme Court decision on patent law, and the first of four Supreme Court cases dealing with the Oliver Evans flour mill patent.
 Like other Supreme Court patent cases prior to "Evans v. Eaton", however, this case did not deal with substantive patent law, but only with issues of statutory construction and infringement liability.

Question: Were United States v. Nixon and Zelman v. Simmons-Harris both US Supreme Court cases?
Answer: yes