Nicola Sacco (died 1927) and Bartolomeo Vanzetti (1888-1927), Italian-born anarchists, became the subject of one of America's most celebrated controversies and the focus for much of the liberal and radical protest of the 1920s in the United States.

The execution of Nicola Sacco and Bartolomeo Vanzetti in Boston in 1927 brought to an end a struggle of more than 6 years on the part of Americans and Europeans who had become convinced that they were innocent of the crimes of robbery and murder. For a sizable portion of the American intellectual community their case symbolized the fight for justice for ethnic minorities, the poor, and the politically unorthodox. The case had a catalytic influence on the subsequent development of leftist thought in America.

Sacco was born in Torremaggiore. When he was 17, he immigrated to the United States. He learned the trade of shoe edge-trimming and settled in Milford, Mass., working for...