The correct answer is: cataloging of people and their work.
'I hear America singing' is a poem by Walt Whitman. His is best known for his patriotic poetry where he prizes America's greatness.
The speaker of the poem announces that he hears 'America singing', and then he describes the people who make the country great every single day. These are the people who contribute to America's life and culture: the mechanics, the carpenters, the masons, the boatmen, the shoemakers, the woodcutters, the mothers. Whitman lists the professions and illustrates briefly what they do, concentrating on the values and virtues of their jobs.
The idea of this poem is that each person has a specific role in life and a voice that belongs only to this person. The author glorifies labor and thinks that all the voices combined is what makes America great and unique.
