I just discovered that one branch of my tree goes back to early puritan settlers who founded New Haven CT. I was able to find published genealogies of several of the family names as well as a history of the region. My thought is that the older it is, the better because it will be closer to the source. I've also heard some horror stories about family histories researched in the late 1800s to early 1900s. The local history book was from 1816 and one of the family books was from 1813, but the others were from 1870 to 1913. Besides (obviously) looking for inconsistencies with other documents, are there any tell tale signs I should watch for in determining accuracies in these books?