Peggy Charren, a children’s TV advocate who was awarded the Presidential Medal of Freedom for her role in bringing monumental changes to programming for young viewers, died Thursday at her home in the Boston suburb of Dedham. She was 86. Her daughter, Deborah Charren Diehl, told the Boston Globe that Charren had suffered from vascular dementia for several years.

Charren co-founded the nonprofit Action for Children’s Television in 1968. After decades of campaigning, the group helped bring about the Children’s Television Act of 1990. The landmark legislation required stations to air educational programming and put sharp limits on the number of commercials that could air during these shows.

“Peggy Charren was TV’s first true kids advocate and someone who we profoundly respected,” Nickelodeon said in a statement. “She was a pioneer who transformed the TV landscape to serve kids with high-quality programming. Her legacy is one that we will always honor and uphold.” Said Disney Channels Worldwide in a statement: “Peggy Charren’s mission was speaking out on behalf of the most impressionable viewers, and her legacy will endure as a greatly respected figure in the transformation of children’s television and the positive potential of media to support early learning.”

Born Peggy Walzer on March 9, 1928, she was raised in NYC and roomed at Connecticut College with future Oscar winner Estelle Parsons. She worked in the film department of WPIX-TV in New York. As a mother of two young daughters, she was appalled by the programs available to them on the Big 3 networks in the pre-Sesame Street era. She described it as “wall-to-wall monster cartoons.” Indeed, the kids shows of the time featured hosts who hawked toys and sugary cereals on the air.

She would become a relentless lobbyist for change, hounding the FCC, members of Congress and network execs. The Action for Children’s Television drew attention to a small clause in the Federal Communications Act of 1934 that required broadcasters using the airwaves to “serve the public interest” if they wanted to keep their licenses. The grass-roots group, which blossomed to 20,000 members, insisted that the mandate be taken seriously, working with educators, religious groups, pediatricians and others.

After some backsliding during the Reagan years, the FCC by 1997 required broadcasters to devote a minimum of three hours per week to educational programming. That year, Charren was appointed to a White House commission on digital TV broadcasting and the public interest.