wow! This is a great question and one that really brings back the memories.

Back in the 1970s, at that age, we had a tiny branch library about three blocks from our home. It was a very quiet, little used library and had some old books in it, including a large set of biographies of famous men. Really something. John Wannamaker, George Washington, Teddy Roosevelt, etc.; the series must've been done in the thirties or forties.