Duncan Phillips acquired Luks's oil Blue Devils on Fifth Avenue at the height of his World War I political efforts. Unable to join the armed forces, Phillips was determined to find ways for American art and artists to serve the cause, organizing exhibitions, including the huge Allied War Salon of 1918, held in New York. In general, the war-theme paintings were disappointing to critics, but Luks's Blue Devils on Fifth Avenue was a brilliant exception. This work portrays the participation of French veterans in the Liberty Loan Drive parade in New York on April 30, 1918. To the strains of the Marseillaise, the soldiers pass by the corner of 45th Street and Fifth Avenue at about nine o'clock in the morning. Harriman National Bank and a synagogue, with flag flying, occupy one corner while Delmonico's Restaurant is situated on the other.
After sketching the event on site, Luks executed this painting specifically for a war exhibition at a New York gallery the following month. He successfully adapted his characteristic spontaneous technique to the festive, patriotic subject. A sense of drama is created by the surge of blue-uniformed figures against the blurry, indistinct background, which is illuminated by the morning sun streaming between the buildings. The impressionistic treatment of the figures, and the use of quick brushstrokes and bright colors, convey a vivid sense of immediacy and motion.
Phillips believed that in Blue Devils on Fifth Avenue Luks effectively conveyed intense "aesthetic emotion…a luxury of resonant color and dramatic light…unusual atmosphere and exciting movement" and he considered the work to be a "masterpiece of impressionistic painting, an important canvas which would have value for its technical qualities alone." He continued his praise with patriotic zeal: "Its chief value for future generations…will be its record of authentic emotion at a thrilling period in history when to a great isolated peace-loving democracy the martial spirit came from the shell-scarred fields of France, and the heart of the great city beat hard with an overflow of affection for these heroes.…"