Primary source documents are original materials created during a specific time period or event. They provide firsthand accounts and direct evidence of historical events, thoughts, or experiences. Examples include letters, diaries, photographs, official documents, and artifacts. These sources are valuable for researchers because they offer insights into the context and perspectives of the time. Researchers use primary source documents to analyze and interpret history. By examining these materials, they can understand the motivations and emotions of individuals involved in events, such as World War II or the Civil Rights Movement. This helps to create a more accurate and nuanced understanding of the past.