By Ariana Bacle
July 31, 2014 at 01:50 PM EDT
Scott Gries/Getty Images

Robert Drew, a filmmaker and pioneer in the cinéma vérité style of documentaries, has died. He was 90.

Drew got his start in the 1950s and broke ground in 1960 with Primary, a documentary that followed the a primary election between Hubert Humphrey and John F. Kennedy that eventually made its way into the Library of Congress’ National Film Registry in 1990.

In addition to being a rare behind-the-scenes look at politics, Primary was notable for its cinéma vérité style, a type of filmmaking that seeks to reveal the truth about its subject. Drew continued to make cinéma vérité films throughout his life, including the Peabody Award-winning 784 Days That Changed America: From Watergate to Resignation and Crisis: Behind a Political Commitment, another one of his films that made it into the Library of Congress.

Drew’s most recent film was 2008’s A President to Remember: In the Company of John F. Kennedya documentary that aired on HBO and was an official selection of that year’s Tribeca Film Festival.