The speaker in Sandburg's "Grass" was the grass.
This was a given in the poem where it stated "I am the grass". Thus, the speaker was the grass.
The grass encouraged the people to pile the bodies for it will cover them all.
David Smith was an American sculptor and painter, best known for his large steel abstract geometric sculptures. One of the most important American sculptors of the twentieth century, he was the first to construct welded metal sculptures in America. His experience working in a car body workshop gave him the skills to use metal as his medium. His first sources of inspiration were the welded-steel industrial sculptures of Pablo Picasso and Julio Gonzalez. These artists, along with the Russian constructivists, inspired him to create these abstract revolutionary art forms.
The form of art depends on the message the artist wants to convey.
hope this helps
