This fill-in timeline is designed to be taught at middle school or high school level. The activity covers Prior events of World War I, The Great Depression, events leading to World War II and WW II. The first two pages are designed for students individually, or in pairs, to fill in after reading the appropriate related text material. This activity is an excellent assessment tool for post coverage of the aforementioned topics/chapters. Pages 3 and 4 provide an instructor-based key to allow for follow-up discussion and checking for understanding. Everything needed to assess student knowledge of the events from 1900 to 1945 are here in one easy-to-use packet. Questions provided on side two of the student handout are developed to encourage students to build critical thinking skills that go beyond the scope of the timeline.