What is the value of an autographed 1897 book Following the Equator by Mark Twain copyrighted by his wife?

The value of an autographed 1897 edition of "Following the Equator" by Mark Twain, particularly if it is copyrighted by his wife, can vary significantly based on factors like condition, provenance, and market demand. Generally, autographed copies of Twain's works can fetch anywhere from a few hundred to several thousand dollars. If the book has unique features or historical significance, its value could be even higher. For an accurate appraisal, consulting a rare book expert or auction house would be advisable.