The price of vigilance

The American Protective League, an army of volunteer sleuths, stepped into the role of providing information on enemy aliens, dissenters, and on private citizens holding unpopular views. Though the 1918 armistice ended the war in Europe, it did not end the silent war at home. The American Protective League was finally disbanded, but its principles flowed into the currents of American ideas, and the organization it spawned continued to influence American though and action.