 He was honored in March 2007 when the United States Postal Service issued a stamp commemorating him.Longfellow's popularity rapidly declined, beginning shortly after his death and into the twentieth century, as academics focused attention on other poets such as Walt Whitman, Edwin Arlington Robinson, and Robert Frost.In the twentieth century, literary scholar Kermit Vanderbilt noted, "Increasingly rare is the scholar who braves ridicule to justify the art of Longfellow's popular rhymings."