"It is a promising reminder of how far we have come as a state since those regretful days in our past," Republican Sen. Arthur Orr said.
The founder of the Scottsboro Boys Museum in Scottsboro, Shelia Washington, said the pardons "give the history books a new ending not guilty."
The Scottsboro Boys case became a symbol of the tragedies wrought by racial injustice. Their appeals resulted in U.S. Supreme Court rulings that criminal defendants are entitled to effective counsel and that blacks can't be systematically excluded from criminal juries.
The case inspired songs, books and films. A Broadway musical was staged in 2010, the same year a museum dedicated to the case opened in Scottsboro.
Five of the men's convictions were overturned in 1937 after one of the alleged victims recanted her story. One defendant, Clarence Norris, received a pardon before his death in 1976. At the time, he was the only Scottsboro Boy known to be alive. Nothing was done for the others because state law did not permit posthumous pardons.
In April, the Alabama Legislature passed Orr's bill to allow the parole board to issue posthumous pardons for old cases where the convictions involved racial discrimination.
The three Scottsboro Boys considered by the parole board on Thursday were Haywood Patterson, Charles Weems and Andy Wright.
The board said the other five Olen Montgomery, Ozie Powell, Willie Roberson, Eugene Williams and Roy Wright weren't eligible under the new law because their convictions were overturned on appeal and the charges dropped.
Washington said some of the Scottsboro Boys changed their names and started new lives. The museum, working with students and faculty members at the University of Alabama, has found the graves of four of the nine. Washington said the next goal is to find all the graves and erect historical markers.
"They didn't know how much they meant in history while they were alive," she said.