(CBS Local)– Mike Wallace is one of the most iconic personalities in television history.

The brash and tenacious journalist made a name for himself at CBS News and his impact is still felt years after his death. Wallace’s story is being told in a new documentary from filmmaker Avi Belkin called “Mike Wallace Is Here.” Belkin had the opportunity to look through hundreds of hours of Wallace’s work with CBS and he quickly learned what made Wallace so great on television.

“I watched interviews for months and wrote down notes of little ideas that I had,” said Belkin in an interview with CBS Local’s DJ Sixsmith. “This was the first time CBS opened up its vault of 60 Minutes. Mike was amazing, he was just relentless. He was focused, locked in and always had a stack of yellow papers with him. He was professional.”

Wallace was one of the original correspondents for CBS when “60 Minutes” launched in 1968. The documentary covers Wallace’s start as a pitchman in commercials, his show Night-Beat, the loss of his son Peter and even his battle with depression and suicide.

“Mike always talked about it as his tipping point in a way,” said Belkin. “That’s the moment when he decided he’s not going to do anymore fluff. He was going to do real, serious journalism. I find it more a symbolic moment. Mike was the master of the tough question. The death of Peter was the moment Mike asked himself the tough question.”

Belkin spent a lot of time watching Wallace interview politicians, entertainers, and people of interest, but his favorite Wallace interview was the one he did with Russian President Vladamir Putin towards the end of his career.

“Maybe my favorite moment in the film,” said Belkin. “Mike was 87 in that interview with Putin. Just seeing him go at Putin at 87 and not holding back. That moment where Mike asks Putin if Russia is a democracy… this is what you dream of an interviewer asking Putin. It was just a reminder of how good he [Mike] was.”

“Mike Wallace Is Here” hits theaters Friday, July 26.