The word "singing" is used in the title to expose the pride an American takes in his work. It is one of the iconic poems written.
<u>Explanation</u>:
Walt Whitman used "singing" in his poem titled "I hear America singing" because in this poem he portrays how different people of America is singing about the pride in their work.
Usually, poets choose the title that should be relevant to the content in the poem. As every people in the poem such as carpenter, mason, boatman, shoemaker etc., is singing about the pride of their job, Whitman titled his poem as "I hear America singing" which also means the whole of America is singing with pride.
Walt uses an established sense of optimism regarding workers and their work.
