What situation is presented in the poem "I Hear America Singing" by Walt Whitman?

"I Hear America Singing" is a hymn of praise to the American worker. At the time when it was written in 1860, the United States was experiencing a rapid rate of industrialization. More people were moving from the country to the cities, performing a wider variety of jobs in the new economy. Whitman's poem reflects this change.
Whitman sets out a long list of various occupations, including carpenters, wood-cutters, plowmen, and mechanics. But they're not just working; they're singing as they work. They all have different jobs and different songs, but their voices come together to provide a harmonious whole. Whatever they do and whatever they sing, all of these workers are American, and their common endeavor is a testimony to American greatness, made greater still by a growing, dynamic economy.
The poem is intensely patriotic but also has a profoundly universal message. Music connects us as human beings, whatever our nationality and whatever we do to earn our daily crust.