This is a monograph accompanying the first major retrospective in 50 years of the work of William Glackens, an important American realist painter. This volume provides a comprehensive introduction to William Glackens (1870-1938), one of the liveliest and most influential American painters of the early 20th century. A founder of the Ashcan School, along with painters such as Robert Henri and John Sloan, Glackens was crucial to the introduction of modern art in the United States through his collaboration with Albert C. Barnes and his championing of landmark exhibitions of American and European avant-garde art.