I thought I'd start by surveying some existing resources.
The Volunteers: Americans Join World War I, 1914-1919, is a free curriculum aligned with U.S. Common Core and UNESCO Global Learning standards for secondary school classrooms worldwide. The curriculum helps students analyze the history of World War I through the lens of volunteer service, both before and after the period of American neutrality, and aims to continue the legacy of volunteerism established during World War I by encouraging students to engage in local, regional, and international service. Learn more about the project, download twenty-two free lesson plans, and visit the Teacher Toolkit for additional resources.
The National World War I Museum and Memorial has great resources, including an interactive timeline, online exhibits and a newsletter for teachers.
As many of you know, World War I was particularly contentious in Montana. German, Irish and Finnish immigrants all questioned the U.S. government's decision to ally with England. Labor organizers--particularly members of the radical Industrial Workers of the World--decried it as a "rich man's war but a poor man's fight." Other Montanans embraced the war with patriotic fervor.
In 1918, the Montana legislature passed the Sedition Act, which made it illegal to criticize the federal or state government, the military, the war, or any war programs. To whit:
"Whenever the United States shall be engaged in war, any person or persons who shall utter, print, write or publish any disloyal, profane, violent, scurrilous, contemptuous, slurring or abusive language about the form of government of the United States, or the constitution of the United States, or the soldiers or sailors of the United States, or the flag of the United States, or the uniform of the army or navy of the United States or shall utter, print, write or publish any language calculated to incite or inflame resistance to any duly constituted Federal or State authority in connection with the prosecution of the War shall be guilty of sedition."
Seventy-nine Montanans were convicted under the act. Was it a necessary wartime measure or an outrageous violation of free speech rights? (Governor Schweitzer, who in 2006 pardoned all those convicted under the law, thought the latter. Governor Stevens, in office when the law was passed, supported it.)
The Sedition Project is a great website for you and your students to use to explore this topic--though certainly one with a point of view. It features information about all of the people convicted under the law, including photographs, occupational information, profiles, prison intake forms, etc. Note that the site does repeat some vulgar language so you may want to preview before sharing with students. The creator of that website, University of Montana professor Clem Works, was also involved in the production of the hour-long documentary, Jailed for Their Words: When Free Speech Died in Wartime America. I found a "for educational use only" copy on YouTube--but no guarantees how long it will stay up. You can also buy the DVD from MontanaPBS.