Based on the old Michigan "postmaster history", this book is very handy for trivia buffs as well. The index is very reliable, I've only noticed a few minor omissions. I give this five stars because it's a nice and nicely sized reference work. It's about the size of one of those car sized phone books that TDI et al make for the cellular phone user and easy to handle. Fascinating and detailed, it is indispensible in its niche. A good companion would be one of the county by county state atlases which shows the locations of the vanished towns, although some of these are so vanished they won't appear on the map.