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.
While primary sources are the original records created by firsthand witnesses of an event, secondary sources are. documents, texts, images, and objects about an event created by someone who typically referenced the primary. sources for their information.