The tone that best describe the tone in this stanza is JOYFUL. It may also be happy.
The word singing has a happy connotation, that could be related to celebration. Indeed, the poem is a celebration of America.
The poem consists of one stanza, which is made up of eleven lines. Whitman writes in his characteristic free verse. The structure is simple.
The tone of the poem is joyful, whimsical, and hopeful. Whitman celebrates in the common American worker.