The NSL reached its highest point of influence in terms of its popular support and the adoption of its policies during World War I. It whipped up Germanophobia with its Committee on Patriotism Through Education, directed by Princeton University professor Robert McNutt McElroy, and it strongly supported the Espionage Act of 1917 and the Sedition Act of 1918. With the support of US Department of Justice, the NSL began to question the patriotism and the loyalty of thousands of Americans suspected of being pro-German or, later, communists. League supporters published newspaper stories or wrote letters to the editor alleging that labor unions, universities, some churches (particularly those with large ethnic German congregations), the League of Women Voters, and a host of other organizations were under communist control.