The most serious defections occurred in the Metals and Machinery, and the Mining Departments. The former department at the outset comprised two groups of metal workers: the United Metal Workers International Union and the Amalgamated Society of Engineers. The United Metal Workers had been a part of the American Federation of Labor until shortly before the first I. W. W. convention, and was on its adjournment installed as a part of the Metals and Machinery Department of the I. W. W. The Amalgamated Society of Engineers had also been a part of the American Federation of Labor.
On account of the somewhat industrial structure of that organization, as different kinds of workers in the metal industry comprised its membership, said society had been suspended ... from the American Federation of Labor, but by a referendum vote of the members living in the United States and Canada it was decided to become an integral part of the American Labor Union....[193]
On the merging of the American Labor Union in the Industrial Workers of the World, the Metal Workers of that union organized in the Amalgamated Society of Engineers were naturally installed with the United Metal Workers in the Metals and Machinery Department. Mutual hostility and friction between these two groups thus arbitrarily forced into one department, added to a deplorable lack of coöperation and assistance from the General Headquarters, finally resulted in the breaking away of the Amalgamated Society of Engineers, and the consequent loss to the I. W. W. of about four thousand wage-earners in this one department during the first year of its existence. This left the Metals and Machinery Department, about three thousand strong, practically limited in membership to the United Metal Workers International Union.[194]
The most paralyzing blow of all came with the loss of the whole of the Mining Department in the defection of the Western Federation of Miners in 1907. Indeed, the Federation really ceased to be an active member of the I. W. W. after the second convention of the latter organization in September, 1906. The W. F. of M. defection was so intimately connected with other dark troubles which came to light at the second convention that the subject will best be treated in that connection.[195]