What do we mean when we say “the nineteenth century”? Where does it begin? Where does it end? What does it contain or exclude? How do we make such choices—on what basis? Surveying four major textbooks, this review offers a look back at the ways these questions have been answered over the past two decades, beginning with the first publication of Robert Rosenblum and H.W. Janson’s 19th-Century Art in 1984 and ending with the second...