[2] English poet John Milton suggested that restricting speech was not necessary because "in a free and open encounter" truth would prevail.
[3] President Thomas Jefferson argued that it is safe to tolerate "error of opinion ... where reason is left free to combat it".
The first reference to the "free trade in ideas" within "the competition of the market" appears in 1919 within US Supreme Court Justice Oliver Wendell Holmes Jr.'s dissent in Abrams v. United States.
[7][8] The actual phrase "marketplace of ideas" first appears in a concurring opinion by Justice William O. Douglas in the Supreme Court decision United States v. Rumely:[9] "Like the publishers of newspapers, magazines, or books, this publisher bids for the minds of men in the market place of ideas.
While the previous cases dealt with natural persons,[citation needed] the 1976 decision Virginia State Pharmacy Board v. Virginia Citizens Consumer Council expanded it to corporations by creating a curtailed corporate commercial speech right, striking down a government regulation of advertising in the process.
[11] It has not been seriously questioned since in United States jurisprudence,[citation needed] but the legacy of those decisions have led to subsequent decisions like Citizens United v. FEC that curtailed the government's ability to regulate corporate speech[11] and much more expansive advertising campaigns, commercial and political than Americans had experienced previously.