Toland may be best known for his Adolph Hitler: The Definitive Biography (1976), an exhaustive study of the German dictator that reprinted texts of many of his speeches, including the earliest ones before he came to power. The book provided many previously unknown details about the man. Toland tried to provide an objective view of Hitler, an effort that drew criticism and accusations of being a Nazi.
Toland also wrote Infamy: Pearl Harbor and its Aftermath (1982), in which he argued that President Franklin D. Roosevelt and top government officials knew in advance that Japan planned to attack the United States but did nothing about it because they wanted war with Japan. It was a position that drew much criticism from historians and journalists.
Toland once said he considered his histories to be drama and he tried to remove himself from the storytelling and let the characters act on their own. He traveled extensively to gather personal accounts and see the places where the history took place.
Toland wanted to become a playwright. When he was 14 years old, a playwright had come to live in his family's home. He was greatly impressed and decided that would be his career. In his senior year in college, he managed a student book store and saved up more than $5,000 to go to Yale Drama School. While he was working he was offered a job by a man from Esso, the oil company (later Exxon), to become a junior executive with a good salary and go to the South Pacific. He refused the offer and the Esso man was incredulous. "What a waste of talent," he said.
Later Toland liked to tell people he made all that money so he could write, not because he liked to make money. "Otherwise, I might have eventually become head of Exxon. Wouldn't that be terrible?"
Toland's early career as a writer was dismal. He wrote 25 plays, six novels and 100 short stories. None of them was ever published. In 1954, he finally sold a short story to American Magazine for $165.
His first published book, Ships in the Sky (1957), was about dirigibles, including the ill-fated Hindenburg, the German passenger airship that caught fire and was destroyed at Lakehurst, New Jersey, in 1937. Toland interviewed survivors and presented a harrowing account of the accident in his book.