What is one theme found in Walt Whitman's "I Hear America Singing"?

I Hear America Singing
by Walt Whitman

I hear America singing, the varied carols I hear,
Those of mechanics, each one singing his as it should be blithe
and strong,
The carpenter singing his as he measures his plank or beam,
The mason singing his as he makes ready for work, or leaves off
work,
The boatman singing what belongs to him in his boat, the
deckhand singing on the steamboat deck,
The shoemaker singing as he sits on his bench, the hatter singing
as he stands,
The wood-cutter's song, the ploughboy's on

Question

What is one theme found in Walt Whitman's "I Hear America Singing"?

I Hear America Singing
by Walt Whitman

I hear America singing, the varied carols I hear,
Those of mechanics, each one singing his as it should be blithe
and strong,
The carpenter singing his as he measures his plank or beam,
The mason singing his as he makes ready for work, or leaves off
work,
The boatman singing what belongs to him in his boat, the
deckhand singing on the steamboat deck,
The shoemaker singing as he sits on his bench, the hatter singing
as he stands,
The wood-cutter's song, the ploughboy's on

otherworldly · Answer

if there are choices please post. if not, well hmmm... im guessing the theme is that everyone has a voice/opinion and they have the right to say something.