This note, written to accompany "The NBA, China, and Social Media: What Are the Rules of the Game?" (UVA-E-0459) but useful in tandem with other cases, charts the history of freedom of speech in the United States. The US Constitution did not originally include the Bill of Rights (which contains the 1st through 10th Amendments), but after more than 200 years of legal and philosophical shifts, expression rights receive legal protection on a tiered system, with political speech enjoying the least abridgment, commercial and sexually explicit expression subject to some government censorship, and obscenity and fighting words enjoying no protection. This note focuses on political speech, summed up in the 1st Amendment: "Congress shall make no law…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." This protection had its challenges over the years, with the most notable blow being the 1798 Sedition Act, which criminalized any questioning of the authority or laws of the US President or Congress. (Congress eventually allowed this act to expire), as well as some 20th century cases (for example, Schenck v. United States, 1919). The note touches on John Stuart Mill's 1859 On Liberty, which made philosophical arguments for the value of free expression that would come to undergird liberal legal interpretations of the 1st Amendment some hundred years later, as well as the repeated infringements of constitutional rights, including free expression during the US Civil War, the Espionage Act of 1917, and the Sedition Act of 1918, and other attempts to suppress free speech. Also referenced is theorist Alexander Meiklejohn, who, in 1949, outlined a highly influential philosophy on the limits of free expression.