Early poetry collections include "Thirty-six Poems" (1935), "Eleven Poems on the Same Theme" (1942) and "Selected Poems, 1923-1943" (1944). "Brother of the Dragon" (1953, revised in 1979) describes the murder of black people by Jefferson's nephew on the Kentucky frontier in the early 19th century, and explores issues such as the nature of evil. The poems in "The Promise" (1957) are active metaphors, beautiful descriptions, and filled with the earthy fragrance of the author's hometown. He won the Pulitzer Prize for Poetry in 1958. There are also poems such as "Now and Then" (1978), "Here" (1980) and "Confirmed Rumors". Warren's novels mainly include "The Night Rider" (1939), "At Heaven's Gate" (1943), "The King's Men" (1946) and "Enough Space and Time" (1950). Later works include "A Group of Angels" (1955), "The Cave" (1959), "The Wilderness" (1961), "The Flood" (1964) and "The Place to Be Lost". Warren was also an important literary critic in the United States in the 20th century. He is the main force of the "New Criticism" that was popular in the United States. "Understanding Poetry" (1938), co-authored with the famous literary critic Brooks, is a masterpiece of the New Criticism theory. In addition, he also wrote "Understanding the Novel" (1943), "A Tribute to Theodore Dreiser" (1971) and "Democracy and Poetry" (1975).