Activist Daniel Smith, One of the Last Children Born to a Parent Who Was Enslaved in the U.S., Dead at 90

Daniel Smith, a civil rights activist and one of the last remaining children of an enslaved Black American, died at age 90 on Wednesday.

Smith's wife since 2006, Loretta Neumann, said her husband had cancer and congestive heart failure, according to The Washington Post.

Neumann told CBS News his daughter April and son Rob were by his side when he died at a hospice in Washington.

Born in Connecticut in March 1932, Smith was the son of former enslaved man, his father Abram Smith (also known as "A.B."), and Clara Smith, the Post reports. His father was 70 years old when his mother — whom Smith reportedly said was white with Scotch-Irish and Cherokee ancestry — gave birth at age 23.

Smith reflected on the lessons he learned from his father, who was born into enslavement in Virginia during the 1860s, in February on CBS Mornings.

"We need more kindness," he said in the interview. "And I look back, in terms of my crazy life, and I think it all came from my father saying, 'Do good things. Do good things.' "

Daniel was an advocate for civil rights throughout his adult life. He participated in the March on Washington in 1963 and marched from Selma to Montgomery, according to the Post, which also reports he met Archbishop Desmond Tutu during South Africa's era of apartheid. He also mingled with civil rights leaders like late Georgia Rep. John Lewis, CBS News reported.

Daniel found other ways to help others, including serving as an Army medic during the Korean War and running both literacy and anti-poverty programs in Alabama, according to the Post.

Later in life, he served as head usher at the Washington National Cathedral, where he wed Neumann.

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Prior to his death, Daniel was working with author Sana Butler to write a memoir titled Son of a Slave: A Black Man's Journey in White America, according to CBS News and the Post.

Butler told the Post that Daniel served as "a reminder that it's impossible" to act as though the history of slavery in the United States does not matter any longer.

In his February interview with CBS Mornings, Daniel acknowledged the progress made in the U.S. since slavery was abolished, but said there is still much work to be done.

"When I voted for [Barack] Obama, I was shaking," he said. "I couldn't believe I was doing this. A Black man? No, we've made a lot of progress."

But, he added, "we cannot continue as a nation with people hating each other."