A History of Just About Everything is an encyclopedia type book for kids. I believe the writing and illustrations are for an elementary audience. It wouldn't be challenging enough or detailed enough for my middle grade children. It starts with the first humans appearing at around 6 000 000 BCE (Evolution of man from apes) and moves through "180 events, people and inventions that changed the world" until it stops at 2011 with the Earthquake in Japan. This is 120 pages of information organized in order by date. It is a timeline through history. This is very useful to see how events, people and inventions from around the globe all relate to one another.
The information on each page isn't very detailed but is certainly gives you enough to see why that event was important to the world. Each page has a highlighted section called Ripples. This ripples section explains how that event "rippled" or affected the future.
I enjoyed looking through this book. I don't claim to to have read every entry yet. I think the events included were excellent choices and they are explained well. It would be a much better read in a book format and not on my computer however. My review copy is in an e-reader format. My kids would also have more access to it if it was in hard copy sitting on our history shelf. I know books like this one get a lot of use as we move through our history studies. But my kids also pick up books like this for fun reading.