From the National Archives including primary sources and online teaching activities:
https://education.blogs.archives.gov/2020/11/09/wwi-resources/
From the Library of Congress:
The Library of Congress offers classroom materials and professional development to help teachers effectively use primary sources from the Library's vast digital collections.
https://www.loc.gov/classroom-materials/world-war-i/
https://www.loc.gov/classroom-materials/world-war-i-what-are-we-fighting-for-over-there/
From the National WWI Museum and Memorial:
From the BBC:
History videos, quizzes and activities that will help students practice their World War I knowledge and skills.
In commemoration of the 100th anniversary of World War I the National History Day Project created this guide:
https://images.history.com/images/media/pdf/history-classroom-WWIGuide.pdf
From the Open Educational Resources Project:
Curricula created by teachers and scholars that offer complete social studies courses aligned to state standards, all totally free. Site includes teaching materials, planning resources, professional-development offerings, and a helpful online teacher community.
These lessons and resources, which explore World War I’s profound political, economic, and social consequences, will help turn this complex period into a manageable narrative students will understand.
https://www.oerproject.com/topics/wwi
Watch YouTube Video: Mobilizing for World War I: America's Draft
Learn about America's draft, literacy and education, and racial disparities from the time period.
https://www.youtube.com/watch?v=zIozarYyOj8&t=42s
Watch YouTube Video: How WWI Changed America: America Goes to War
Learn how President Woodrow Wilson moved the United States from neutrality to involvement in the war.
https://www.youtube.com/watch?v=GyEqUvij4Bo&t=4s
War Untold Website
War Untold is a place to share the stories of those courageous members of the armed services who served their country during the First World War (1914-1919). This website is not designed to tell the story of the war, but to share these few individuals' experiences through their own memorabilia, letters, images from the past, and present day images taken on walks on the Western Front.