Unless you know the title and/or author of the book you are looking for, history topics should be searched by Keywordto maximize the number of references to a topic.
Another way to search is to browse by Subject. You can search the Subject term "Revolutionaries" to find books about Revolutionary leaders from other countries and other eras.
The word "sources" appearing next to an entry is usually a good indication that the text is at least in part a primary source. You can increase your chances of turning up primary sources by adding terms such as "sources," "letters," "diaries," etc. to your keyword search term.
Most books about French History are found in the "DC" section of the Library.