of Labor had actively undermined FOTLU and raided its unions during the previous five years. The Knights had provided scab workers to employers during strikes called by FOTLU unions. The Knights had publicly denounced FOTLU initiatives, legislative proposals and organizing efforts. Now the Knights began to support a breakaway group of radical cigar-makers known as the Progressive Cigar-makers' Union. With their base in Chicago, the Progressive Cigar-makers advocated open rebellion against the capitalist system. The local central labor body, the Amalgamated Trades and Labor Assembly, fought the Progressive Cigar-makers bitterly for the allegiances of the Chicago's unions. The Knights openly supported the Progressive Cigar-makers against CMIU, enraging Gompers. In the midst of the battle among the Progressive Cigar-makers, CMIU and the Amalgamated Trades, the May 1, 1886 deadline came and with it the general strike. During a peaceful labor rally protesting police violence against strikers in Chicago on May 4, a bomb was set off—killing one policeman immediately (seven others later died of their injuries. In what later became known as the Haymarket Riot, police opened fire on the crowd. Another 11 people were killed, and dozens more wounded. A large number of the unions participating in the strike on May 4 were FOTLU locals. A political backlash against the American labor movement erupted nationwide. In the wake of the Haymarket Riot, FOTLU proposed on April 25, 1886, that a truce be established between the Knights and the federation. A letter signed by McGuire of the Carpenters; Adolph Strasser, president of CMIU; Josiah B. Dyer, general secretary of the Granite Cutters; P.J. Fitzpatrick, president of the Iron Molder's Union of North America; and W.H. Foster, secretary of FOTLU, called for a meeting to be held on May 18, 1886 in Philadelphia, Pennsylvania. Labor peace was the public purpose of the Philadelphia meeting. But Gompers and the meeting convenors planned to use the meeting to swing union support toward an entirely new labor federation. Gompers believed that the Knights were threatening the very existence of craft unionism, and their radical attitudes were likely to bring the wrath of governmental authority down on the labor movement in the wake of the Haymarket Riot. Twenty delegates representing more than 365,000 workers met in Philadelphia. The delegates proposed that the Knights 'agree that they would not initiate into the Order any trade union member without the permission of his union, or any other wage