To find books, first use the library's catalog (you may wish to expand the search from Wilmington to the UNC Library Consortium. Then use WorldCat to expand the search further, to over 9,000 libraries worldwide.
As you search for books, be sure to look at books about the genre your title fits within, and books about the type of author who wrote your book. This will help provide context for your author's works. For instance, when doing research on Charles Waddell Chesnutt, look at works on African American literature and African American authors.
Consider the historical topics included in your book. As you perform keyword searches to research the history, be sure to look at the subject headings on relevant books. Using these headings will likely improve the relevance of your search, especially in WorldCat.
Also search for the papers of the author's colleagues. For instance, correspondence with Chesnutt is included in the papers of Booker T. Washington.
Use Google Books to find sources that mention your author and the work you are researching. If the full text is not provided by Google Books, use WorldCat to find the book in a library and request through Interlibrary Loan (ILLiad).