The Treaty of Versailles in the mind of the Germans stabbed them in the back, especially the guilt clause that made them take blame for the First World War. Hitler capaitalized on these sentiments and used them to rally the German people.
Primary sources are the first hand evidence left behind by participants or observers at the time of events. Primary sources originate in the time period that historians are studying. They vary a great deal.
Primary sources help students relate in a personal way to events of the past and promote a deeper understanding of history as a series of human events. Because primary sources are snippets of history, they encourage students to seek additional evidence through research.