Answer:
The man the dust now represents is Abraham Lincoln.
Step-by-step explanation:
The poem "This Dust Was Once the Man" by Walt Whitman is an elegy, which means it honors the life and memory of a dead person. This poem, just like "O Captain! My Captain" honors the American president Abraham Lincoln. Whitman refers to Lincoln as "gentle, plain, just, and resolute," which are in fact qualities for which the president was well known.
There are different interpretations of what "the foulest crime in history" means. Some say it refers to the attempt of secession by the southern states. Others claim that it refers to Lincoln's assassination.