References to the American poet Hart Crane (1899-1932) persist throughout Sophie's Choice. As well as Leslie, the double agent Irena killed by Jozef has 'this expertise in a poet named Hart Crane' (p. 435).
Crane's Modernist poetry is highly stylised and very demanding. It has been compared to the writing of T.S. Eliot, who was a profound influence. Crane suffered from depression, and committed suicide by jumping from a steamship in the Gulf of Mexico.