"December 1941: 31 Days That Changed America and Saved the World" is a powerful account of the days leading up to, and the days immediately after, the Japanese bombing of Pearl Harbor and subsequent entry of the United States into World War II.
This 500+ page book (600 if you count the notes) has a very simple format: it devotes one chapter to each day of the month of December 1941. The chapters describe the events of each day, either directly or indirectly related to the coming war.
Of all the things I learned, I was especially surprised that, prior to December 7, the mindset of many Americans was not in favor of the United States entering the war. We are used to such things regarding the Vietnam war and the wars in Iraq and Afghanistan, but the image we tend to get of 1940's America is that of solidarity. In fact, the national mood changed quite a bit as of December 7, but even then, it wasn't a case of undisputed unity.
The stories and information in "December 1941" are excellent. I received a copy of this book for free for review purposes, with no obligation to deliver a positive assessment. Still, I highly recommend it for anyone interested in history, especially World War II buffs.