1964: The poll tax is eliminated by the ratification of the twenty-fourth amendment to the Constitution. Throughout the summer, many volunteers travel to Mississippi, Alabama, and Georgia to promote voting rights among African Americans. In Mississippi, three civil rights activists are murdered.

Today: The right to vote is assured to African Americans.

1964: Interracial marriages are banned by sixteen states, mostly in the South.

Today: No state bans interracial marriages.

1964: Anti-apartheid leader Nelson Mandela is sentenced to life in prison for his activities in South Africa.

Today: After being imprisoned for twenty-six years, Mandela was released in 1990. He was elected as South Africa's president in 1994. He has since retired from public life.