Whitman hears America singing: not one anthem but many voices at once — the mechanic, the carpenter, the mason, the boatman, the shoemaker, the mother, the young woman sewing — each carolling «what belongs to him» as they work.
The poem is a catalogue, Whitman's favourite figure: he lists trades and people until the sum makes a portrait of the country. What each one sings is distinct and their own, and that variety — not uniformity — is what democracy sounds like to Whitman. By day the trades; at night, the chorus of young fellows.