great prosperity immediately following the war the unions, all told, had at least 5,500,000, of which 4,078,740 were in the A. F. of L. in 1920. Since then the unions have lost almost 50 per cent of their effectives. Of the present membership, approximately 270,000 are in Canada.
Trade union organization is concentrated chiefly in those industries where skill still plays a large part. The unskilled industries, with but few exceptions, are almost entirely unorganized. The most strongly organized industry is the building trades. The unions control most of the big industrial centers and are able to insist upon strong union agreements with the employers. In the smaller towns the degree of organization is much lower in the building trades, as in all others. The largest union in the industry is the carpenters (United Brotherhood oi Carpenters and Joiners) numbering 350,000. Altogether the building trades have 800,000 members. The coal miners (United Mine Workers), are a powerful union with 400,000 members out of a total of 800,000 employed in the industry. The printing trades number 125,000, of whom about half are in the International Typographical Union, which, like all the printing unions, is affiliated to the A. F. of L. The clothing trades are strongly organized. During the war and for a year or two afterward, the railroad unions were very strong, about 1,500,000 out of a total of 1,800,000 workers being affiliated to them. But they lost heavily as a result of the economic depression and the ill-fated strike of the mechanics in 1922–23. At present all the organized railroad workers do not number more than 600,000, and these are contained mostly in the telegraphers and the four independent brotherhoods of train. service workers. The textile industry, with 1,000,000 workers, has only about 75,000 organized, and these arein several rival unions. The shoe and leather industry is only about 10 per cent unionized. The great oil, steel, meat packing, metal mining, auto-
