Anarchists split from the Socialist Labor Party to form the Revolutionary Socialist Party in 1881. By 1885 they had 7,000 members, double the membership of the SLP. They were inspired by the International Anarchist Congress of 1881 in London. There were two federations in the United States that pledged adherence to the International. A convention of immigrant anarchists in Chicago formed the International Working People's Association (Black International), while a group of Native Americans in San Francisco formed the International Workingmen's Association (Red International). Following a violent demonstration at Haymarket in Chicago in 1886, public opinion turned against anarchism. While very little violence could be attributed to anarchists, the attempted murder of a financier by an anarchist in 1892 and the 1901 assassination of the American president, William McKinley, by a professed anarchist led to the ending of political asylum for anarchists in 1903. In 1919, following the Palmer Raids, anarchists were imprisoned and many, including Emma Goldman and Alexander Berkman, were deported. Yet anarchism again reached great public notice with the trial of the anarchists Sacco and Vanzetti, who would be executed in 1927.