The ceremony is scheduled for 10 a.m. at Broad Street Historical Park in Greenwood.
Although the slogan "black power" had been used by prominent figures such as New York congressman Adam Clayton Powell and author Richard Wright, it became part of America's lexicon in 1966 after Stokely Carmichael spoke at a Mississippi rally.
Carmichael and others, including the Rev. Martin Luther King Jr., had taken up James Meredith's one-man freedom march, halted when Meredith was shot by a sniper. Meredith was the first black to attend the University of Mississippi.
On June 16, 1966, when Carmichael, chairman of the Student Nonviolent Coordinating Committee, was released from jail after being arrested for trying to pitch tents on the grounds of the Stone Street Negro Elementary School in Greenwood, Miss., he told a crowd he was frustrated with the slow pace of the freedom fight. Then he yelled:
"What we're gonna start saying now is black power."
An aide took up the chant. The crowd called back.
"Black power" became part of America's lexicon. Historians say Carmichael's frustration was shared by many young blacks who had become disenchanted with King's turn-the-other-cheek philosophy. King initially opposed the black power slogan. King initially opposed the black power slogan.