This is an interesting item. It's about a lately rediscovered letter from Upton Sinclair - author of the great novel The Jungle, an exposé of the Chicago meat-packing industry - indicating that he knew about the guilt of Sacco and Vanzetti.
"I faced the most difficult ethical problem of my life at that point," he wrote to his attorney. "I had come to Boston with the announcement that I was going to write the truth about the case."There's further discussion here and here. (Thanks: SE.)Other letters tucked away in the Indiana archive illuminate why one of America's most strident truth tellers kept his reservations to himself.
"My wife is absolutely certain that if I tell what I believe, I will be called a traitor to the movement and may not live to finish the book [Boston]," Sinclair wrote Robert Minor, a confidant at the [Communist] Daily Worker in New York, in 1927.
Update on February 3 2006: See now here. The report quoted above has been exposed as tendentious.