Primary sources are original records or firsthand accounts. Designation as a primary source may depend on context, focus and perspective, and time of study. Typically, a primary source is from the same time period as the subject studied. If sources provide interpretation or analysis, they may be secondary sources. Context is important for distinguishing between a primary or secondary source.
The Scottsboro Boys in their own words by 
They shall not die! : The story of Scottsboro in pictures : Stop the legal lynching! by Look for firsthand accounts, reports from government and agencies, and other documents that publish original material, including newspapers from the period.
The Constitution of the United States: A Transcription from the National Archives