In 1977, gay activist Harvey Milk (Sean Penn) wins a seat on the San Francisco Board of Supervisors. His political career and private life unfolds as he finds himself in conflict with anti-gay singer Anita Bryant (shown in archived footage), conservative fellow supervisor Dan White (Josh Brolin), and Proposition 6 proposer John Briggs (Denis O'Hare).

Milk was filmed from an original script by Dustin Lance Black and based upon new interviews with Harvey Milk's surviving friends and associates.Because much of the film's action concerns interaction between people who now are dead, much of Milk is speculative fiction based upon fact.

Harvey Milk (1930-1978) was a gay activist elected to public office in California in 1977 as a member of the San Francisco Board of Supervisors. He was assassinated a year later by Dan White, a former San Francisco supervisor. Milk was the first openly gay person elected to major office in the US and has become an important figure in gay history.

From his 1970 meeting Scott Smith (portrayed by James Franco) in NYC to the candlelight vigil two days after his assassination in San Francisco in 1978.

In 1977, conservative California state senator, John Briggs, proposed an initiative which would have prohibited men and women suspected of homosexuality from obtaining or keeping jobs teaching in California's public schools. After filing petitions bearing a half-million signatures, Prop 6 (aka the "Briggs Initiative") qualified for the November 1978 ballot. Newly-elected city supervisor Harvey Milk debated Senator Briggs and publicly campaigned against his initiative. Analysts predicted a narrow defeat for the measure at best. Following a nationwide opposing campaign (publicly championed by counter-culture music industry fund-raising events), nearly 60% of California voters rejected the initiative.

General time-line of other political issues mentioned in this film:

1969, June — The Stonewall riots in Greenwich Village against police harassment outside gay bars (where it had been illegal to serve alcohol to a known gay and illegal for same-gender couples to dance together publicly).

1973 — San Francisco's first "Gay Freedom Day Parade" held in Civic Center.

1977 — singer Anita Bryant launched her unsuccessful "Save Our Children" campaign to make it illegal for gays to teach in Miami and Dade county, Florida (countered by the "We Are Your Children" campaign).

1978 — Prop 6, "Briggs' Initiative," defeated. 18th November, the Peoples' Temple tragedy in Guyana (involving hundreds of San Francisco Bay Area natives). 27th November, the assassinations of Mayor George Moscone and supervisor Harvey Milk by former supervisor Dan White at City Hall.

The events in the film's coda:

1979, May — a peaceful march from the Castro to City Hall protesting the leniency of Dan White's sentence (manslaughter rather than premeditated murder) erupts into the "White Night Riots" upon reaching City Hall (resulting in retaliatory police rioting in the Castro later the same night).

1984 — Dan White paroled after serving 5 years of a 7-year sentence for manslaughter.

1985 — Dan White committed suicide in his estranged wife's garage in San Francisco.

Just as it happened in real life, Dan White shoots and kills Harvey Milk after also assassinating Mayor George Moscone. The film then flashes back to a scene from Milk's 40th birthday in which he tells lover Scott Smith that he doesn't expect to live to be 50. It then switches to scenes of the thousands of mourners comprising the candlelight vigil moving down Market Street from Castro Street to the City Hall as Milk, in a voiceover, finishes his dictation into the tape recorder. A note then appears reading: "Over 30,000 people marched from the Castro to the City Hall to honor slain Supervisor Harvey Milk and Mayor George Mosconi." Epilogues then follow in which the fate and faces of each of the principal characters is detailed.

DAN WHITE's lawyers argued that his diet of junk foods created a chemical imbalance that led to the killings. The press coined it "The Twinkie Defense". A jury of Dan White's peers found him guilty of manslaughter, the minimum charge for both murders. The verdict set off The White Night Riots, the most violent uprising in the history of the gay movement. The next day, not a single arrest was made. In 1984, after serving only five years, Dan White was released from prison. Less than two years later, he returned to San Francisco and committed suicide. SCOTT SMITH worked tirelessly to preserve and continue Harvey's legacy. He died of AIDS-related complications in 1995. ANNE KRONENBERG is now the mother of three and Deputy Director of the Department of Public Health in San Francisco. JIM RIVALDO and DICK PABICH formed their own consulting firm in the Castro, lifting San Francisco's most progressive candidates to public office for two decades. DANNY NICOLETTE is a professional photographer who has documented the lesbian, gay, bisexual, and transgender movement for over 30 years. In 1987, CLEVE JONES created the NAMES project AIDS Memorial Quilt, which remains an internationally recognized symbol of the HIV pandemic. Cleve continues his political activism today. Just past the Golden Gate Bridge, amidst a shower of grape Kool-aid, Doonesbury cartoons and bubble bath, Harvey's closest friends scattered his ashes out at sea.

The use of the "Twinkie Defense" during the trial is an urban legend. White's defense team never, as is alleged in the movie's footnote, suggested that Twinkies snack cakes caused Dan White to kill Harvey Milk. Instead they argued that White was suffering from diminished capacity due to clinical depression. As part of the evidence for this depression, they pointed to White, who had previously been a health nut, consuming large amounts of junk food such as Twinkies. One of the defense psychologists testified that massive quantities of junk food could have exacerbated White's depression. In reality, Twinkies were presented as a symptom and not a cause of White's mental imbalance.

For the Californian civics of 2008; Prop 8 was to, if ratified by the people, make it so that "Only marriage between a man and a woman is valid or recognized in California." The subject had/has been of interest to anybody who wanted to start a family with another member of the same sex; a thing largely of interest to gay or lesbian people. From the onset of production in Autumn 2007 (many months earlier than any legislation had been proposed for the 2008 election ballots), the film's release dates had been intended to coincide with other planned dedication ceremonies and memorials of the thirtieth anniversary of the City Hall murders and all post-production and screening events were aimed near 27 November 2008.

First and final segments are "Infinite Descent" from Thomas Newman's soundtrack to HBO's Angels in America (2003). The one that's featured right in the middle of the trailer is "Almost Martyrs" by Alex Parker, composed for the soundtrack of The Life of David Gale (2003).

"Queen Bitch", from David Bowie's 1971 album Hunky Dory

(1) The beginning and end of Act III of Giacomo Puccini's 1900 opera, "Tosca", (2) As Scott Smith moves out, Harvey Milk plays an LP record of tenor Giuseppe di Stefano performing the aria, E lucevan le stelle, and (3) As Harvey Milk watches a performance of the opera, extra Catherine Cook appeared on stage as Nelly Miricioiu's voice was heard (from the TOSCA recording on the Naxos label, which was listed in the credits even though the names of Miricioiu and tenor Miroslav Dvorsky were not).