(lot of common objects have been enumerated in the previous line

(lot of common objects have been enumerated in the previous lines, and here are the last two lines of the poem.)
"The horizon's edge, the flying sea-crow, the fragrance of salt marsh and shore mud.
These became part of that child who went forth every day, and who now goes, and will always go forth every day.
Questions:
A.Who is the author of this poem? What is the title of the poem?
B.What does the child stand for in the poem?
C.How do you understand"These became part of the child"?
【正确答案】：A.Whitman, There Was Child Went Forth
B.the young,growing America
C.The common objects in the poem reflect the natural process of a boy's growth.