CNN  — 

Two towering figures of the American civil rights movement died Friday, a major loss for a nation still grappling with protests and demands for racial equality decades later.

Vivian passed away at his Atlanta home of natural causes Friday.

“He was the sweetest man,” Kira Vivian said. “He was so loving. What a loving dad. He was the best father throughout my entire life.”

His civil rights actions started decades ago with his first nonviolent protest in 1947 – a lunch counter sit-in in Peoria, Illinois.

The minister participated in his first nonviolent protest, a lunch counter sit-in in Peoria, Illinois, in 1947, according to the National Visionary Leadership Project.

Vivian had a strong religious upbringing and he and other ministers founded the Nashville Christian Leadership Conference, an affiliate of the Southern Christian Leadership Conference. The group helped organize sit-ins and civil rights marches.

Black leaders, including CT Vivian, left first row, march down Nashville's Jefferson Street at the head of a group of 3,000 demonstrators April 19, 1960, and head toward City Hall on the day of the Z. Alexander Looby bombing.

That same year, he and other ministers founded the Nashville Christian Leadership Conference, an affiliate of the Southern Christian Leadership Conference, NVLP said. The group helped organize the city’s first sit-ins and civil rights march.

Some of the marches ended in violence against him. He once led a group of people to register to vote in Selma, Alabama, despite defiance by a local sheriff who blocked the group.

Vivian also created a college readiness program to help care for children kicked out of school for protesting racism.

The US Department of Education used his program as a guide to create Upward Bound, which was designed to improve high school and college graduation rates for students in underserved communities.

In the late 1970s, Vivian founded an anti-racism organization that focused on monitoring the Ku Klux Klan.

“We called it the Center for Democratic Renewal because the whole culture had to be renewed if it truly was going to be a democratic one.” Vivian said they viewed the Center For Democratic Renewal as “the political side” of what they were doing with the SCLC, which was focused on the country’s morality struggles during the civil rights movement.

Obama awarded him the Presidential Medal of Freedom in 2013.

About her father, Kira Vivian said, “he was just a kind person and cared about people.”

Vivian was born in Boonville, Missouri, on July 30, 1924. He and his late wife, Octavia Geans Vivian, had six children.

CNN’s Alta Spells contributed to this report.