March 6, 1857: In the case of Dred Scott v. Sanford, the U.S. Supreme Court rules that slaves are not citizens and cannot expect protection from the federal government or courts.

Jan. 1, 1863: President Abraham Lincoln issues the Emancipation Proclamation, ordering that all slaves within rebellious areas "are, and henceforward shall be free."

Dec. 6, 1865: The 13th Amendment to the U.S. Constitution is ratified, putting an end to slavery.

July 9, 1868: The 14th Amendment to the U.S. Constitution is ratified, guaranteeing the liberties and rights granted by the Bill of Rights to freed slaves.

Feb. 3, 1870: The 15th Amendment to the U.S. Constitution is ratified, granting the right to vote to African-American men.

Aug. 18, 1920:The 19th Amendment to the U.S. Constitution is ratified, granting the right to vote to all women.

May 17, 1954: In Brown v. Board of Education, the U.S. Supreme Court rules unanimously that school segregation violates the 14th Amendment. A year later, the court would order an end to school segregation "with all deliberate speed."

Dec. 1, 1955: Rosa Parks, a 42-year-old NAACP member, refuses to give up her seat on a Montgomery, Ala., city bus to a white passenger, touching off a bus boycott that would not end until buses were desegregated on Dec. 21, 1956.

Sept. 24, 1957: President Dwight D. Eisenhower issues Executive Order 10730, sending federal troops to Little Rock, Ark., to maintain order and peace as Central High School is integrated.

Aug. 28, 1963: An estimated 250,000 people, a fifth or more of them white, gather for the March on Washington, which featured the Rev. Martin Luther King Jr.'s "I Have a Dream" speech.

Sept. 15, 1963: A bomb goes off at 16th Street Baptist Church in Birmingham, Ala., killing four young girls and touching off riots in the city.

July 2, 1964: President Lyndon B. Johnson signs the Civil Rights Act of 1964.

March 7, 1965: Demonstrators begin a march from Selma, Ala., to Montgomery, Ala., to press for voting rights, but 50 marchers are hospitalized after being stopped at the Edmund Pettus Bridge by police officers wielding whips, clubs and tear gas. The encounter, which became known as "Bloody Sunday," is credited with winning support for a voting rights law enacted five months later.

Aug. 6, 1965: President Lyndon B. Johnson signs the Voting Rights Act, largely to enforce the 15th Amendment ratified 95 years earlier.

April 4, 1968: The Rev. Martin Luther King Jr. is assassinated in Memphis, setting off riots around the country.

Oct. 24, 2005: Rosa Parks dies at 92.

Jan. 30, 2006: Coretta Scott King, wife of the slain civil rights leader, dies at 78.

Aug. 28, 2008: Sen. Barack Obama accepts nomination of the Democratic Party for president.

Nov. 4, 2008: Obama is elected as the first black president.