Old Books - 1880 - 1920

[schuyler101]

A friend of mine flips houses for a living and knowing my love for books gave me a library of them from one of the houses.

There are some very old books in this collection and I'm trying to assess their worth and figure out what the best way to sell them is.

I can't find most of these books on amazon and they pre-date ISBN numbers so finding accurate information on them is difficult.

Any guidance or resources would be greatly appreciated. I'm not even sure how to accurately gauge condition of these books. Some seem to be in very good condition, some not so much.

I don't want to just drop these off with used bookseller and take whatever they give me and be potentially ripped off. I may have something valuable on my hands here.

Here are some specific books I have:

"Threads of Thought (or Familiar Words on Common Themes)" by Charles Rogers - 1888, London by S.W. Partidge and Co., 9 Paternoster Row
The cover is a bit stained but is in ok condition and the inner pages seem to be in very good condition

4 books by George Trumbull Ladd, all published at Longmans, Green and Co. NY
What May I Hope? - 1915
What Ought I to do? - 1915
What Should I Believe? - 1915
What Can I know? - 1917 - This one has a handwritten note from the author, he appears to have given the set to someone as a gift. The note is signed by him and dated 1918

All seem to be in pretty good condition

I'm posting from the office and these are the books I have with me, I have more than 100 more similar to them at home but don't have the foggiest idea how to start selling these.

Thanks in advance.