Congratulations you wrote a great book. How long is that book copyright protected according to the US Copyright Office?

In the United States, a book is copyright protected for the life of the author plus 70 years after their death. If the work is created by multiple authors, the copyright lasts for 70 years after the death of the last surviving author. For works created by corporate authorship, the copyright lasts 95 years from publication or 120 years from creation, whichever is shorter.