On the 50th anniversary of the Freedom Summer, the movement to register thousands of African-American Mississippi voters who had been systematically prevented from registering to vote, veteran documentarian Stanley Nelson has made what will surely stand as a defining record of that effort. There’s nothing flashy or stylistically groundbreaking about Freedom Summer, which takes Nelson’s typically no-nonsense approach to meticulously researched storytelling through copious interviews and mountains of archival footage. To that end, he rounds up organizers of the effort, the students who participated, and even a member of the opposition, a representative from the all-white “Citizens’ Council” that was part of the effort to stymie the black vote. The history—from the uneasy meshing of cultures as white college kids from the North roomed with African-American families in Mississippi, to the violent clashes with local authorities—is well-related, but it’s the interviews that give Freedom Summer its emotional heft. While the voter drive itself wasn’t hugely successful, it was a key moment in the Civil Rights movement. It’s in those personal reflections, captured on camera after a half-century of progress (the recent Supreme Court gutting of the Voting Rights Act notwithstanding), that Freedom Summer really shines.