Answer:
The book contains photocopies of Jefferson’s original letters. Not only are these letters Jefferson’s actual words, but the copies also present his words in his own handwriting. While the page isn’t the actual letter, Jacob is quoting Jefferson’s actual words and thoughts. Therefore, the book is a primary source document.
Explanation:
Two circumstances fits with the question:
1 - if the chapter's authors based their conclusions on their analysis of primary sources related to the Russian Revolution of 1917
2 - if that chapter were being read to understand how American educators taught Russian history in the 1960s.
The 1960s in America were a confusing period under the shadow of the Cold War. The United States and the Soviet Union were fighting ideologically to prove which system - Capitalism or Communism - was the best. Each side attempted to show the problems and mistakes of each economic system, sometimes almost reaching to fight fiscally. Because of all these misunderstandings and attacks of both sides, it's necessary to be careful with all the material produced at that time, especially a textbook, because the content can be tendencious, and mislead the reader. We ONLY could consider this textbook relevant if the authors were correct on their sources, writing based on researches, and if this textbook would be used to understand how Russian history was taught in the 1960s. Because one way or another, this textbook is outdated a lot!