Schenck v. United States, 249 U.S. 47 (1919) , is a United States Supreme Court case concerning enforcement of the Espionage Act of 1917 during World War I.
 A unanimous Supreme Court, in an opinion by Justice Oliver Wendell Holmes, Jr., concluded that defendants who distributed fliers to draft-age men, urging resistance to induction, could be convicted of an attempt to obstruct the draft, a criminal offense.
 The First Amendment did not alter the well-established law in cases where the attempt was made through expressions that would be protected in other circumstances.
 In this opinion, Holmes said that expressions which in the circumstances were intended to result in a crime, and posed a "clear and present danger" of succeeding, could be punished.
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.
Oliver Wendell Holmes Jr. ( ; March 8, 1841 – March 6, 1935) was an American jurist who served as an Associate Justice of the Supreme Court of the United States from 1902 to 1932, and as Acting Chief Justice of the United States from January–February 1930.
 Noted for his long service, his concise and pithy opinions and his deference to the decisions of elected legislatures, he is one of the most widely cited United States Supreme Court justices in history, particularly for his "clear and present danger" opinion for a unanimous Court in the 1919 case of "Schenck v. United States", and is one of the most influential American common law judges, honored during his lifetime in Great Britain as well as the United States.
 Holmes retired from the Court at the age of 90 years, making him the oldest Justice in the Supreme Court's history.
 He also served as an Associate Justice and as Chief Justice on the Massachusetts Supreme Judicial Court, and was Weld Professor of Law at the Harvard Law School, of which he was an alumnus.
"Imminent lawless action" is a standard currently used that was established by the United States Supreme Court in "Brandenburg v. Ohio" (1969), for defining the limits of freedom of speech.
 "Brandenburg" clarified what constituted a "clear and present danger", the standard established by "Schenck v. United States" (1919), and overruled "Whitney v. California" (1927), which had held that speech that merely advocated violence could be made illegal.
 Under the imminent lawless action test, speech is not protected by the First Amendment if the speaker intends to incite a violation of the law that is both imminent and likely.
 While the precise meaning of "imminent" may be ambiguous in some cases, the court provided later clarification in "Hess v. Indiana" (1973).
 In this case, the court found that Hess's words did not fall outside the limits of protected speech, in part, because his speech "amounted to nothing more than advocacy of illegal action at some indefinite future time," and therefore did not meet the imminence requirement.
Freedom for the Thought That We Hate: A Biography of the First Amendment is a 2007 non-fiction book by journalist Anthony Lewis about freedom of speech, freedom of the press, freedom of thought, and the First Amendment to the United States Constitution.
 The book starts by quoting the First Amendment, which prohibits the U.S. Congress from creating legislation which limits free speech or freedom of the press.
 Lewis traces the evolution of civil liberties in the U.S. through key historical events.
 He provides an overview of important free speech case law, including U.S. Supreme Court opinions in "Schenck v. United States" (1919), "Whitney v. California" (1927), "United States v. Schwimmer" (1929), "New York Times Co. v. Sullivan" (1964), and "New York Times Co. v. United States" (1971).
Brandenburg v. Ohio, 395 U.S. 444 (1969) , was a landmark United States Supreme Court case based on the First Amendment to the U.S. Constitution.
 The Court held that government cannot punish inflammatory speech unless that speech is "directed to inciting or producing imminent lawless action and is likely to incite or produce such action."
 Specifically, it struck down Ohio's criminal syndicalism statute, because that statute broadly prohibited the mere advocacy of violence.
 In the process, "Whitney v. California" (1927) was explicitly overruled, and doubt was cast on "Schenck v. United States" (1919), "Abrams v. United States" (1919), "Gitlow v. New York" (1925), and "Dennis v. United States" (1951).
Gravel v. United States, 408 U.S. 606 (1972), was a case regarding the protections offered by the Speech or Debate Clause of the United States Constitution.
 In the case, the Supreme Court of the United States held that the privileges and immunities of the Constitution's Speech or Debate Clause enjoyed by members of Congress also extend to Congressional aides, but not to activity outside the legislative process.
Charles T. Schenck was the secretary of the Socialist Party of America in Philadelphia during the First World War and involved in the 1919 Supreme Court case "Schenck v. United States".
Rodríguez v. Popular Democratic Party, 457 U.S. 1 (1982) , was a case in which the Supreme Court of the United States heard on appeal from the Supreme Court of Puerto Rico whether Puerto Rico may by statute vest in a political party the power to fill an interim vacancy in the Puerto Rico Legislature.
 The Supreme Court of Puerto Rico held that such a procedure did not violate the United States Constitution, and the US Supreme Court upheld the decision of the Supreme Court of Puerto Rico.
 The case was of some interest to close followers of the Court as it featured the one and only return of former associate justice, Abe Fortas, now in private practice, at oral argument on behalf of the appellee.
"Shouting "fire" in a crowded theater" is a popular metaphor for speech or actions made for the principal purpose of creating unnecessary panic.
 The phrase is a paraphrasing of Oliver Wendell Holmes, Jr.'s opinion in the United States Supreme Court case "Schenck v. United States" in 1919, which held that the defendant's speech in opposition to the draft during World War I was not protected free speech under the First Amendment of the United States Constitution.

Question: Which US Supreme Court Case occurred first, Gravel v. United States or Schenck v. United States?
Answer: Schenck v. United States