To protest local resistance to black voter registration in Dallas County, Alabama, the Southern Christian Leadership Conference (SCLC) organized a mass march from Selma to Montgomery on March 7, 1965. Under the leadership of John Lewis of the Student Nonviolent Coordinating Committee and the SCLC's Hosea Williams, a column of five hundred to six hundred demonstrators marched without incident through the streets of Selma until reaching the Edmund Pettus Bridge where they were brutally attacked by state troopers and mounted patrolmen. Television cameramen captured the incident on film, and "Bloody Sunday," as it came to be known, helped marshal nationwide support for the passage of voting rights legislation. Undeterred by the threat of violence, Martin Luther King Jr. led more than three thousand marchers across the Edmund Pettus Bridge only two weeks later. From there, King's column made the 54-mile trek to the state capital under the watchful protection of the recently federalized Alabama National Guard, arriving in Montgomery four days later.