Mark Twain's first book, The Innocents Abroad or the New Pilgrims' Progress, was a huge success. Even today people love reading an American's take on the "old world".
This is one of my all-time favorite books. There's no plot, no mystery, no surprise ending. It's not a novel, it's one of Mark Twain's five books of travel. The others are Life on the Mississippi, A Tramp Abroad, Following the Equator, and Roughing It. They are all memoirs, or travel logs.