In the early decades of the 20th century, Grenville L. Winthrop, a New Yorker and Harvard graduate, assembled a remarkable collection of paintings and drawings by French, British and American artists of the 19th century. They include the finest group of works by Ingres outside France and major canvasses and sheets by David, Gericault, Delacroix, Moreau and Renoir. British works, beginning with Blake and Flaxman, include important Pre-Raphaelite paintings...