Letters from Hawaii is a collection of 25 letters that Mark Twain wrote from Hawaii in 1866 as a special correspondent for the Sacramento Union newspaper. The 25 letters, written during Twain's four-month visit, were not published as a book until 1947. During his four-month and a day stay in the Hawaiian Islands, then called the Sandwich Islands, Twain visited the islands of Oahu, Maui, and Hawaii.