In pre-internet days, genealogists would salivate when they located a published family history pertaining to their own ancestors. I have distinct memories of finding books written about my Scripture family, the Knapps, and many others.
It also used to be that one had to visit a library – or many libraries – in person in order to be able to read these histories.
Today, many people don’t do their own research. Information is copied and pasted with little thought to its accuracy. Some of those mistakes could be avoided by reading a published family history that is 150+ years old. Yes, there are many books published in the 1800s that can support or debunk family lore!
Granted, some books are limited in scope, covering perhaps the lines of only the eldest son in each generation or even just one man, part of a larger family, and his descendants. However, other family histories are so complete that, in one or more giant volumes, every descendant, male and female, is traced as far as possible. A number of these books even include photographs of some of the notable family members.
Yet, I never hear anyone talking about great information they’ve found in one of these books!
I’ve used many such books in my research, so I’d like to share several to give an idea of what might be found.
I mentioned my Knapp family. Arthur Mason Knapp published a 77-page book in 1909:

The Descendants of Samuel Scripture of Groton, Massachusetts: [90 pages]

Some Descendants of John Shepley, Salem, Massachusetts, Immigrant, 1635: [44 pages]

A History of the Stanwood Family in America: [350 pages]

The Coleman Family, Descendants of Thomas Coleman of Nantucket: [48 pages]

A contribution toward a genealogy of all Torreys in America: [230 pages]

Last, but not least, a book by myself, which is accessible on FamilySearch: The Williams Family of Cumberland County, Virginia, 187 pages when published and which today is 244 pages long:

Many of the copyright-free books were published in the 1800s, but there are many excellent family histories published in the 1900s right up until today. Those books will mostly be under copyright restrictions for many years, but are well worth checking WorldCat and major genealogy libraries to locate a copy.
Just because a book was published in 1850, don’t ignore it, thinking there is no good information to be found. Some of these smaller one-name publications include details such as occupation, descriptions of land owned, hints to ancestral homes, militia service (not necessarily war service) and town offices held. Bits of information like these aren’t always easily found.
Some of the books published in the latter half of the 20th century, but pre-internet, even include data on living persons.
Of course, just as with online trees, just because it’s “published” doesn’t mean it is 100% accurate. Genealogists need to do due diligence, but family histories really are treasure not to be overlooked.