This document provides an introduction to modern art and highlights several influential artworks from different movements including Neo-Classicism, Romanticism, Early Photography, Realism, and Impressionism. Key works mentioned include Jacques-Louis David's Oath of the Horatii, Eugene Delacroix's Liberty Leading the People, John Constable's The Hay Wain, Louis Daguerre's Boulevard du Temple, Paris, and Claude Monet's Boulevard des Capucines, Paris. The document traces the evolution of modern art styles from the late 18th to early 20th centuries.