Being a big fan of alternate history, I picked up What If?, What If? 2, and What If? American History several years ago. These books are not fictional stories about characters in alternate history scenarios nor are they alternate history tales written as factual history. These books contain essays by leading historians examining different historical events and then looking at what might have happened if this or that were different. Because I like history in general I really liked many of the essays in these volumes. I learned a lot about actual historical events while also learning about what ifs.
The first two books contain essays on a variety of events from the ancient world until the twentieth century. Many of the usual suspects are here: The American Revolution, Napoleon, the American Civil War, WWI and WWII, and the Cold War. There are also essays on Alexander the Great, the Romans, the Mongols, the Spanish at the height of their power, China, England, and other American events after the American Revolution.
Most of the essays are interesting in their own coverage of historical events. I learned a lot about parts of history I was not familiar with. In general I liked the military event essays more than the non-military ones. It could be because I am a big fan of military history, but also some of the other stories just were not as interesting and some were biased one way or another in their coverage.
If you like reading about history you will probably like these books just for their discussions of historical events. The what if questions are an added bonus.