What is the author's style in Franklin D. Roosevelt and the New Deal, 1932-1940 by William E. Leuchtenburg?

This book is written from the third person point of view and that is that of the author, William E. Leuchtenburg. The book tells the story of the first two years of the Roosevelt administration. This is the period of the programs of deficit spending that became known as the New Deal Programs. These are the programs that were implemented to solve the economic problems of the nation.