Carlo Tresca was born in Italy and moved to the United States in 1904 to escape a jail sentence for libel associated with the paper he was editing at the time.

Though he started as a Socialist, Tresca died an Anarchist. He edited a number of papers which stood up for workers' rights and denounced the hypocrisy and corruption of those in power. One of his favorite targets was the clergy who he attacked relentlessly. Tresca was also a skilled labor agitator, leading strikes and urging workers to stand up for their rights.

Dorothy Gallagher's book All the Right Enemies--The Life and Murder of Carlo Tresca is an excellent history of Tresca's life, as is the more recent biography by Nunzio Pernicone, Carlo Tresca: Portrait of a Rebel. Gallagher says in her preface, "to thousands of Italian immigrants Tresca was a hero; to the FBI he was 'notorious'; to a number of American intellectuals and labor leaders he was a counsel; to American and Italian fascists, a serious adversary; to the Communist party of the 1930s a renegade and Trotskyite; to rival anarchists, a spy and traitor; to his friends a joy; to women, overpoweringly attractive; to the man who killed him, little more than a contract." Given this, there can be little doubt that Tresca was a man who was as respected as he was hated, and ultimately hated enough to be murdered.