The Innocents Abroad, or The New Pilgrims' Progress is a travel book by American author Mark Twain. Published in 1869, it humorously chronicles what Twain called his "Great Pleasure Excursion" on board the chartered vessel Quaker City (formerly USS Quaker City) through Europe and the Holy Land with a group of American travelers in 1867. The five-month voyage included numerous side trips on land. The book, which sometimes appears with the subtitle "The New Pilgrim's Progress", became the best-selling of Twain's works during his lifetime, as well as one of the best-selling travel books of all time.