But now, the Associated Pressreports, the Justice Department has reopened its investigation, citing "new information" in the notorious murder case that galvanized the Civil Rights Movement.
The renewed investigation was first revealed in a recent federal report, which didn't specify what new information investigators were acting on.
The report doesn't indicate what the new information might be. She inspires a movement that elevated Martin Luther King to world historical status, passed the Civil Rights Act and the Voting Rights - that national infrastructure was built by the Till case.
Not even a month after the boy's body was pulled from the river, an all-white jury acquitted Carolyn Bryant's husband, Roy, and another man, J.W. Milam, of Emmett's murder, despite eyewitnesses identifying the defendants.
A MS prosecutor declined comment Thursday on whether federal authorities had given him new information since they reopened the probe. The pair later confessed in a paid magazine interview to abducting and killing the teenager. "We're happy to have that be the case so that ultimately or finally someone can be held responsible for his murder", said Johnson, who leads the Cold Case Justice Initiative at Syracuse University.
The Justice Department declined to comment Thursday, but it appeared that the government had chosen to devote new attention to the case after Donham, in an interview with Tyson, recanted parts of her account of what transpired in August 1955. But Parker says the discussion likely occurred after the release of a book that raised questions about the Till case previous year. The government has investigated 115 cases involving 128 victims under the "cold case" law named for Till, the report said. Jackson's slaying was an impetus for the Selma-to-Montgomery voting rights march later that year.
"None of us wants to do anything that jeopardizes any investigation or impedes, but we are also very interested in justice being done", she told the outlet, declining to discuss specifics. His murderers then strapped a cotton gin fan to his neck with barbed wire so it would weigh him down when they tossed him in the Tallahatchie River.
Till's remains were returned to Chicago where his mother insisted on a public funeral service with an open casket.
Donham, then 21 and known as Carolyn Bryant, testified in 1955 as a prospective defense witness in the trial of Bryant and Milam.
"We don't know anything". The two men have since died, in 1994 and 1981, respectively.
"He said, 'How about a date, baby?'" she testified, according to a trial transcript released by the Federal Bureau of Investigation a decade ago. In the book, author Tyson wrote that Donham told him her testimony about Till accosting her wasn't true.
"What's the matter baby, can't you take it?", she claimed he said.
The woman - Carolyn Bryant - reportedly told her husband and brother that Emmett had groped her, made crude remarks, and wolf-whistled at Carolyn.
Till's cousin, Wheeler Parker, said Thursday he's "pretty sure" an investigator asked him about what happened in a MS store the day Till whistled at a white woman before his slaying in 1955.
The evidence, which was heard after jurors had been sent out, was ruled inadmissible by the judge.