The Port Huron Statement was drafted and supported by the Students for a Democratic Society in 1962. The document was primarily by Tom Hayden, who has spent a lifetime in left-wing political activism. The statement calls for participatory democracy, meaning that people should be more involved in the politics. Its main concerns are civil rights, nuclear warfare, and the hypocrisy of social norms--as one source states, the gulf between what we say ("all men are created equal") and what we practice (segregation and discrimination).
You can read the full text of the statement at Tom Hayden's official web site: