What is the valley of love

is this from a book or something?

Explanation:

in our power to make a world happy - to teach mankind the art of being so - to a character hitherto unknown - and to have, as it were, a new creation intrusted to our hands, are honors that command reflection, and can neither be too highly estimated,

many battles and wars (such as the one at gettysburg), are commemorated by statues or monuments, with some areas preserved as monuments and national parks. do you think this contradicts the message of "grass"? in at least 200 words, explain your thinking and cite evidence from the poem to support your opinion.