When we think about the civil rights movement now, it's often with removed, rose-tinted glasses filled with images of stirring speeches and impressively organized marches.

However, the reality of the movement, and particularly the summer of 1964, is both more tedious and more tragic. It's filled with volunteers who tirelessly pounded the pavement to organize voter registration and carefully prepared for the violence that was sure to ensue.

Check out some very rare footage of that summer and the story that shook a nation and the world — the story of three missing volunteers who gave the ultimate sacrifice for equality.