Modern astronomy came mostly from the discovery that the earth was revolving around the sun and not the sun around the earth. The church claimed before that the earth is in the middle of the universe and that the sun goes around it, however, astronomers of the time managed to prove that the earth was in fact revolving around the sun.
The cartoon's shadows suggest that some people living in the United States — especially the wealthy — perhaps had forgotten where they came from and that their families were once immigrants just like the new arrival in the cartoon.
