What does the child stand for in the poem?

(A 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. ” 
What does the child stand for in the poem?
【正确答案】：

THE YOUNG, GROWING AMERICA

【题目解析】：诗中的“child”指的是年轻的，成长中的美国。