In England, where the struggle for press freedom first began, the appearance of unauthorized publications resulted in a royal proclamation (1534) requiring prepublication licensing. Stronger restrictive measures were taken by the later Tudor and Stuart monarchs, and censorship came to be applied more to political criticism than religious heresy. John Milton, in his Areopagitica (1644), attacked the licensing law and called on Parliament to suppress offensive publications after their appearance if necessary. Milton's objections to prior restraint eventually became a cornerstone of press freedom, but it was not until 1695 that the licensing and censorship laws were abolished.

Severe restrictions on the press continued, however, in the form of seditious libel laws under which the government was able to arrest and punish any printer who published material in any way critical of the government. There was no clear definition of what constituted seditious libel, and in the 18th cent. the printing of parliamentary debates had to be disguised as debates between classical figures. At this time, both true and false criticism of the government was considered libel. In fact, legal doctrine proclaimed that the greater the truth the greater the libel. Only in the mid-19th cent. did truth become admissible as a defense in English libel cases.

The defense of John Peter Zenger against libel charges in 1735 is often seen as the cornerstone of American press freedom. After the American Revolution, several states provided for freedom of the press, and the First Amendment (1791) to the U.S. Constitution declared that Congress shall make no law … abridging the freedom of speech or of the press. Whether these acts were intended to prohibit prosecution for seditious libel or merely to prohibit prior restraint has been a matter of controversy. In reaction to the Sedition Act (1798), a more libertarian interpretation of the First Amendment became dominant, which saw it as rejecting seditious libel as a crime. The First Amendment was later (beginning in the 1920s) applied to all the states by judicial interpretation of the Fourteenth Amendment (1868).

Wartime situations often present challenges to the legal limits of press freedom. What was looked upon as irresponsible reporting during the Civil War led to attempts by civil and military authorities to impose restrictions upon the press. Appeals by the War Department for publishers to voluntarily suppress news that was strategic to the war were, however, largely ineffective. During World War I, near hysteria over the possibility of sabotage led Congress to pass the Espionage Acts (1917) and the Sedition Act (1918). These acts limited freedom of the press to such an extent that not only was censorship exercised against pro-German publications but also against German-language publications and those advocating socialism or pacifism.

In 1931, the Supreme Court, in Near v. Minnesota, for the first time declared almost all forms of prior restraint to be unconstitutional. In World War II the Office of Censorship, under the direction of Byron Price, expanded upon techniques developed by George Creel's Censorship Board of World War I. The new office supervised (1941–45) the most comprehensive censorship in U.S. history. Compliance was voluntary, however, and was based on the office's suggestion to editors on topics to avoid. Because Price and his assistants were respected journalists themselves, newspapers and journals cooperated. Similar cooperation was accorded to the Office of War Information, which controlled the flow of news from government agencies. As a result, the government rarely took punitive action.

After the war, many news organizations undertook campaigns against secrecy in government, maintaining that the withholding of public records threatens freedom of the press. As world tensions heightened during the cold war in the 1950s and 60s, defense officials often protested that the mere absence of war did not justify peacetime openness in the press.

In the late 1960s and early 70s, there were frequent charges and countercharges between journalists and government officials concerning the withholding of information on the Vietnam War by the government. The only recognized grounds for prior restraint, national security, was tested in 1971 when Daniel Ellsberg, a former government employee who believed that information that should be made public was being withheld by the government, released the Pentagon Papers, a collection of classified government documents concerning the Vietnam War. The government tried to block their publication, but the U.S. Supreme Court, in New York Times Co. v. United States (1971), permitted their release.

The First Amendment has not been extended to the gathering as well as the publication of news. The experience of the Vietnam War led the U.S. government to restrict the access of reporters in combat areas in subsequent military encounters. This practice, used during the 1983 invasion of Grenada and the 1991 Persian Gulf War, was bitterly resented by many reporters. In domestic affairs, although a number of states have passed shield laws, which permit journalists to refuse to disclose confidential information and sources to law-enforcement bodies, the U.S. Supreme Court has recognized no unrestricted right of press confidentiality.