The First Amendment to the US Constitution
"Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances."
See WikipediaPetition and assembly
The right to petition the government extends to petitions of all three branches of government: the Congress, the executive and the judiciary. According to the Supreme Court, "redress of grievances" is to be construed broadly: it includes not solely appeals by the public to the government for the redressing of a grievance in the traditional sense, but also, petitions on behalf of private interests seeking personal gain. Nonetheless, in the past, Congress has directly limited the right to petition. During the 1790s, Congress passed the Alien and Sedition Acts, punishing opponents of the Federalist Party; the Supreme Court never ruled on the matter. In 1835 the House of Representatives adopted the Gag Rule, barring abolitionist petitions calling for the end of slavery. The Supreme Court did not hear a case related to the rule, which was abolished in 1844. During World War I, individuals petitioning for the repeal of sedition and espionage laws were punished; again, the Supreme Court did not rule on the matter.
The right of assembly was originally distinguished from the right to petition. In United States v. Cruikshank, 92 U.S. 542 (1875), the Supreme Court held that "the right of the people peaceably to assemble for the purpose of petitioning Congress for a redress of grievances, or for anything else connected with the powers or duties of the National Government, is an attribute of national citizenship, and, as such, under protection of, and guaranteed by, the United States." Justice Waite's opinion for the Court carefully distinguished the right to assemble, labeled a secondary right, from the right to petition, a primary right. Later cases, however, paid less attention to these distinctions.