In the early years of World War I, Rupert Brooke achieved renown throughout the English-speaking world for his sonnet sequence "1914," in which he sang of his devotion to England in emotion-laden lines that possessed, it seemed to many wartime readers, an immortal beauty and permanent significance; England's handsome singer of romantic verse had been transformed by the crisis into a soldier poet. It was, therefore, a great tribute to Alan Seeger that he was called the American Rupert Brooke.

The title fitted him, albeit somewhat loosely, for unlike the "realistic" or antiwar poets of World War I, such as Siegfried Sassoon and Wilfred Owen, Seeger, like Brooke, adhered to the meters and diction of earlier poets and viewed the conflict in a romantic light: it was a crusade and a way of achieving a noble death. Enlisting in the French Foreign Legion in 1914, he expressed, to an unusual...