Dear Mr. Rosenwald by 
The Education of Blacks in the South, 1860-1935 by 
The Rosenwald Schools of the American South by 
You Need a Schoolhouse by 
Edwin Rogers Embree: the Julius Rosenwald Fund, Foundation Philanthropy, and American Race Relations by 
A secondary source is not a first-hand or eyewitness account. This source is one step removed from the primary source. It's written after the fact. Think of a secondary source as an interpretation or analysis of a primary source. A journal article may rely on primary sources, but the article itself is a secondary source. An author who studies the speeches and diaries of a subject, and then writes a book, is creating a secondary source.
So what's a tertiary source? It's the source such as a catalog, bibliography or index that leads the researcher to primary and secondary sources.
