The general type of labor organizations in the United States is according to craft. Thus, for example, in a given city there are as many labor unions as there are trades or crafts represented among the laborers of the city. The members of each trade forming a local union unite with the local union of workers of the same trade in other cities of the state to form a state federation for that particular trade. The members of the trade in the various states together, sometimes with organizations from Mexico or Canada or other foreign countries, unite to form a national or international union for the particular trade. Nearly all of these national and international unions unite again to form the American Federation of Labor. Thus it will be seen that in this type of labor organization the grouping is by trades or crafts instead of by localities.

A second type is that of the older Knights of Labor and of the more recent Industrial Workers of the World. Here the organization of the workers is made irrespective of the trade at which they are employed. In the case of the latter mentioned organization the local unit is the industrial establishment and not the trade; that is, all of the workers in the same establishment belong to the same union whether they are bricklayers or masons or carpenters or plasterers or what not. The ideal of the Industrial Workers is to unite these local groups into "one big union" irrespective of craft lines. At the present time the idea of one big union does not make a strong appeal to the skilled workers generally because they prefer to retain their craft form of organization.