Earlier that year incumbent President Lyndon B. Johnson had announced he would not seek reelection, thus making the purpose of the convention to select a new presidential nominee for the Democratic Party.

The event was among the most tense and confrontational political conventions in American history, and became notorious for the televised heavy-handed police tactics of the host, Mayor Richard J. Daley of Chicago.

[19] Johnson, despite spending the week at his Texas ranch, maintained tight control over the proceedings, going so far as to have the Federal Bureau of Investigation illegally tap Humphrey's telephones to find out his plans.

[20] Humphrey previewed his platform to two of Johnson's more hawkish advisers, Secretary of State Dean Rusk and National Security Advisor Walt Whitman Rostow.

[23] Humphrey later stated that his biggest mistake of the election was to give in to Johnson, contending that if he stuck to his original platform it would have shown his independence and given him a lead in the polls.

[23] Humphrey always believed that if he had given his planned speech (which he instead gave in Salt Lake City on September 30, 1968) calling for an unconditional bombing pause of North Vietnam as "an acceptable risk for peace", that he would have won the election.

[24] Complicating the election was the third party candidacy of Alabama governor George Wallace, who ran on a white supremacist platform promising to undo the changes of the Civil Rights Movement.

[21] Humphrey had been well known as a liberal supporter of the Civil Rights Movement, and he felt that with Nixon and Wallace competing for the conservative white Southern voters there was no realistic opportunity for him to appeal to that group.

The leaders of the Yippies (Youth International Party), Abbie Hoffman and Jerry Rubin, specialized in outlandish, bizarre rhetoric to provoke media attention, and Daley took many of their outrageous threats seriously.

[44] With the convention taking place days after the Warsaw Pact invasion of Czechoslovakia, Eric Sevareid stated that Chicago "runs the city of Prague a close second right now as the world's least attractive tourist destination".

[44] On the second night of the convention, CBS News correspondent Dan Rather was grabbed by security guards and roughed up while trying to interview a Georgia delegate being escorted out of the building.

On the last night, NBC News switched back and forth between images of the violence to the festivities over Humphrey's victory in the convention hall, highlighting the division in the Democratic Party.

[47] Daley's security measures were so intense that it was not possible to walk across the convention floor without jostling other delegates, which added to the tensions as Democrats fiercely argued about whether to accept Johnson's war plank to the platform.

[48] Robert Maytag, the chairman of the Colorado delegation asked: "Is there any rule under which Mayor Daley can be compelled to suspend the police state terror being perpetrated at this minute on kids in front of the Conrad Hilton [hotel]?

[52] In 1968, the Yippies and the National Mobilization Committee to End the War in Vietnam (MOBE) had already begun planning a youth festival in Chicago to coincide with the convention, and other groups such as the Students for a Democratic Society (SDS) would also make their presence known.

[53] Two SDS leaders, Tom Hayden and Rennie Davis, had planned to keep their protests peaceful, although the lack of permits and threats of violence by the Chicago police made this unlikely to happen.

[57] The leaders of the Yippies (Youth International Party), Abbie Hoffman and Jerry Rubin, attempted to provoke authorities by proclaiming: "We are dirty, smelly, grimy and foul...we will piss and shit and fuck in public...we will be constantly stoned or tripping on every drug known to man".

[45] Surrounded by reporters on August 23, 1968, Yippie leader Rubin, folk singer Phil Ochs, and other activists held their own convention with their candidate Pigasus, an actual pig.

[59] In the evening, a demonstration was held at Grant Park opposite the Hilton Hotel, which was peaceful as bands such as Peter, Paul and Mary played folk music.

[62] The police regained control of the situation after firing tear gas and chased the demonstrators down the streets, beating them with clubs and rifle butts and arresting them.

[29] The police assault in front of the hotel during the evening of August 28 became the most famous image of the Chicago demonstrations of 1968, as the entire event took place live under television lights for seventeen minutes while the crowd chanted, "The whole world is watching".

[61] Samuel Brown, one of the organizers for Senator McCarthy, lamented the violence, saying: "Instead of nice young people ringing doorbells, the public saw the image of mobs shouting obscenities and disrupting the city".

[18] The general feeling at the time was the hippies were intent upon destroying everything good in America and the Chicago police had acted correctly in beating such dangerous anti-social types bloody.

[65][66] The Walker Report, "headed by an independent observer from Los Angeles police – concluded that: 'Individual policemen, and lots of them, committed violent acts far in excess of the requisite force for crowd dispersal or arrest.

[24] By contrast to the violence and chaos in Chicago, the Republican convention in Miami had been a model of order and unity, which made Nixon appear better qualified to be president as even Humphrey himself conceded in private.

[24] On September 30, 1968, Humphrey gave a speech in Salt Lake City that he had intended to deliver at the convention in Chicago, saying he was willing to unconditionally stop the bombing of North Vietnam to break the deadlock in the peace talks in Paris.

[73] A grand jury charged eight defendants with conspiracy, crossing state lines with intent to incite a riot, and other federal crimes following the 1968 Democratic National Convention.

The defendants became known as the Chicago Eight: Abbie Hoffman, Jerry Rubin, Tom Hayden, Bobby Seale, Rennie Davis, David Dellinger, John Froines, and Lee Weiner.

The changes imposed by the commission required that the number of delegates who were Black, women, Hispanic and between the ages of 18 and 30 reflected the proportion of the people in those groups in every congressional district.

[79] The changes brought about by the commission ended the ability of local bosses who headed political machines such as Daley to ensure delegations that were subservient to them attended conventions.