See his Collected Poems (1916) and his letters and diary (1917).
Seeger entered Harvard in 1906 after attending several elite preparatory schools, including Hackley School. At Harvard, he edited and wrote for the Harvard Monthly. After graduating in 1910, he moved to Greenwich Village for two years, where he wrote poetry and enjoyed the life of a young bohemian.
During that time, he attended soirées at the Mlles. Petitpas' boardinghouse (319 West 29th Street), where the presiding genius was the artist and sage John Butler Yeats, father of the poet.
Having moved to the Latin Quarter of Paris to continue his seemingly itinerant, intellectual lifestyle, on August 24, 1914, Seeger joined the French Foreign Legion so that he could fight for the Allies in World War I (the United States did not enter the war until 1917). He was killed in action at Belloy-en-Santerre, famously cheering on his fellow soldiers in a successful charge after being hit several times himself by machine gun fire. One of his more famous poems, Rendezvous, was published posthumously. Indeed, a recurrent theme in both his poetic works and his personal writings prior to falling in battle was his desire for his life to end gloriously at an early age.
Seeger's poetry was not published until 1917, a year after his death. Poems, a collection of his works, was relatively unsuccessful, due, according to Eric Homberger, to its lofty idealism and language, qualities out of fashion in the early decades of the twentieth century.
Poems was reviewed in The Egoist, where the critic commented that "Seeger was serious about his work and spent pains over it. The work is well done, and so much out of date as to be almost a positive quality. It is high-flown, heavily decorated and solemn, but its solemnity is thorough going, not a mere literary formality. Alan Seeger, as one who knew him can attest, lived his whole life on this plane, with impeccable poetic dignity; everything about him was in keeping." The man who wrote this review of Poems was T. S. Eliot, Seeger's classmate at Harvard.
In the 1993 film In the Line of Fire, the assassin Mitch Leary (played by John Malkovich) cites "Rendezvous" as president John F. Kennedy's favorite. He incorrectly titles the poem by its first line, "I have a rendezvous with death," adding that it is "not a good poem."