The late 19th-century the United States is probably best known for the vast expansion of its industrial plant and output. There were many machines had replaced skilled people since machines works faster. I think until now-21st century, they’re still trying to invent new machines to develop industry and economy. According to Laurence Shames “Frontier, for most of the world’s people, does not suggest growth, expanse, and opportunity. For Americans, it does, and has always” (p.85). For Americans, they always want more and never feel enough. Because they live in a country that is on top of the world, they want to keep this country being strong and rich forever. It’s easy to understand since most of people can’t be satisfied with what they have,
