The American Federation of Labor (AFL) and the Industrial Workers of the World (IWW) had several key differences. Based on the options provided, the statement that best captures a primary difference is:
It allowed only skilled workers to join.
The AFL primarily represented skilled workers and focused on economic gains through collective bargaining, while the IWW sought to unite all workers, including unskilled laborers, and aimed to overthrow capitalism. The AFL focused on achievable gains like higher pay and better working conditions, often avoiding strikes, while the IWW was more radical in its approach and used strikes as a key tool for social change.