Galleani and his group promoted radical anarchism by speeches, newsletters, labor agitation, political protests, secret meetings, and, above all, direct action, often referred to as propaganda of the deed.

Many used bombs and other violent means to promote their political position, practices that Galleani actively encouraged but in which he apparently did not participate, except for writing the bomb-making manual La Salute è in voi!.

The Galleanisti were a group of Italian anarchists and radicals in the United States who followed Luigi Galleani and his message of "heroic" violence in the face of capitalist oppression.

[1] For the part of his followers, Galleani prompted a symbolic war that continued after his deportation and the raid on the offices of his newspaper, Cronaca Sovversiva.

[3] Galleani attracted numerous radical friends and/or followers into the Galleanisti, including Frank Abarno, Gabriella Segata Antolini, Pietro Angelo, Luigi Bacchetti, Mario Buda (also known as "Mike Boda"), Carmine Carbone, Andrea Ciofalo, Ferrucio Coacci, Emilio Coda, Alfredo Conti, Nestor Dondoglio (also known as "Jean Crones"), Roberto Elia, Luigi Falzini, Frank Mandese, Riccardo Orciani, Nicola Recchi, Giuseppe Sberna, Andrea Salsedo, Raffaele Schiavina, Carlo Valdinoci, and, most notably, Nicola Sacco and Bartolomeo Vanzetti.

[8] The plant coordinated a trap for an attempted bombing at St. Patrick's in March 1915 that involved fifty disguised officers and caught Frank Abarno and Carmine Carbone.

[11] Their trial revolved around La Salute è in voi and the defendants' right to read any books of any kind, including bomb-making handbooks.

[2] One Chicago-based Galleanist, chef Nestor Dondoglio, known by the alias Jean Crones, laced soup with arsenic in an attempt to poison some 100 guests, all figures in industry, business, finance, or law, at a banquet in 1916 to honor Archbishop Mundelein.

[16] About 60 Galleanisti left for Mexico following the April 1917 American entry into World War I and Galleani's advice to avoid draft registration.

Their motives for emigrating varied from draft evasion to fighting the then-ongoing Mexican Revolution to preparing for an expected revolutionary moment in Italy.

[17] Mario Buda is thought to have constructed[18][19][20] the large black powder bomb[21] with an acid "delay" detonator[22] that exploded on November 24, 1917 at a Milwaukee police station.

The bomb appeared to have been directed at Reverend August Giuliana, who had recently led a street revival meeting opposed by local anarchists.

[25] In late 1917 and early 1918, bombings occurred in New York City, San Francisco, Washington, D.C., Boston, and Milwaukee that were later attributed to Galleanists, but no criminal prosecutions followed.

On January 17, 1918, a 19-year-old Galleanist, Gabriella Segata Antolini, was arrested for transporting a satchel filled with dynamite, which she had received from Carlo Valdinoci.

Mills, and Judge Robert von Moschzisker were heavily damaged by explosive bombs filled with metal slugs, an act later attributed to the Galleanist group.

[28][29] The next night four Galleanists who had attended the rally attempted to place a bomb at the American Woolen Co. mill in nearby Franklin, whose workers were on strike.

[4] An early lead to the identity of the bombers was revealed when one package bomb was found addressed to a Bureau of Investigation (BOI) field agent, Rayme Weston Finch.

[4] No one was killed by the mail bombs that were delivered, but a black housekeeper, Ethel Williams, had her hands blown off when she opened a package sent to the home of Senator Thomas W. Hardwick, a sponsor of the Immigration Act of 1918.

[4] Among the intended victims were politicians who had endorsed anti-sedition laws and deportation, or judges such as Charles C. Nott, who had sentenced anarchists to long prison terms.

Thompson, Massachusetts State Representative Leland Powers, and Attorney General A. Mitchell Palmer, already a previous target of a Galleanist mail bomb, were attacked.

None of the officials was killed, but the explosions killed William Boehner, a 70-year-old night watchman, who had stopped to investigate the package left on Judge Nott's doorstep,[31][32] as well as one of the most wanted Galleanists – Carlo Valdinoci, a former editor of Cronaca Sovversiva, and a close associate of Galleani, who blew himself up as he laid a package bomb at the door of Attorney General Palmer's home.

There will have to be bloodshed; we will not dodge; there will have to be murder: we will kill, because it is necessary; there will have to be destruction; we will destroy to rid the world of your tyrannical institutions.Police eventually traced a flyer accompanying the bombs to the print shop where Andrea Salsedo, a typesetter, and Roberto Elia, a compositor, were arrested.

Elia was deported; according to his lawyer, he turned down an offer to remain in the United States if he would deny his connection to the Galleanists, asserting that his refusal to talk "is my only title of honor".

[3] In 1927, more bombings were attributed to Galleanists, especially as several court and prison officials were targeted, including Webster Thayer, the trial judge in the Sacco-Vanzetti case.