This dust was once the man

this dust was once the man,
gentle, plain, just and resolute, under whose cautious hand,
against the foulest crime in history known in any land or age,
was saved the union of these states

walt whitman

what is the word just most likely an allusion to?

a. lincoln's career as a lawyer

b. lincoln's death at war's end

c. whitman's war reporting

d. whitman's poem writing