NEW YORK — In April of 1968, Martin Luther King Jr. was shot and American cities burned in rage. In California, a 42-year-old teacher and mother of three felt helpless.

"I remember sitting in suburbia saying, is there anything I can do?" said Harriet Glickman.

She wanted to reach someone with influence, so she wrote to Charles Schulz. His "Peanuts" comic strip was read by nearly 100 million people each week. The characters — Charlie Brown, Lucy, Linus — were all white. So Glickman told Schulz he should integrate.

Harriet Glickman. CBS News

"He said he felt he couldn't do it, it might be condescending," Glickman said.

Then he thought better of it and wrote back, saying he drew an episode that he thought would please her. On a beach, an African-American child named Franklin returned a ball Charlie Brown had lost. Civil rights had come to the comics.

"I thought, that's like me," said Robb Armstrong, who was just six when the character was introduced.

The power of the newest character was unmistakable.

Franklin was the first black character to appear in the "Peanuts" comic. CBS News

"My mom is like, 'Look that's a little black character in "Peanuts."' I was like 'Wow!' This changed everything," Armstrong said.

He would become a highly successful cartoonist himself, drawing "JumpStart" for three decades.

As for Harriet Glickman, she wants everyone to know that "everybody can make a difference."

"Franklin is this big," Glickman said with her fingers an inch apart. "And Franklin made a difference."

Not all pictures are worth a thousand words. Some speak volumes more.