Coretta Scott King

The third of four King children, the 62-year-old died from prostate cancer at his home in Malibu, Calif., according to the King Center, where he served as chairman.

Four days after her husband was killed, Coretta Scott King led a march in Memphis. The act reflected her role as a partner in the struggle for civil rights. "I was impelled to come," she said.

After Warren quoted Coretta Scott King and Sen. Edward Kennedy, Republicans invoked a Senate rule that silences a member accused of impugning the integrity of a colleague.

Warren was reading aloud from a letter by the widow of Dr. Martin Luther King Jr. when she was interrupted by the presiding chair of the Senate.