As the 19th century began, America was prospering in terms of new inventions, trading, and production of goods, resulting in the Industrial Revolution. As this was happening, Americas desire to expand westward increased a lot and the idea of Manifest Destiny was born. As Amy Greenberg, author of Manifest Destiny and American Territorial Expansion: A Brief History with Documents, generally stated that the idea of Manifest Destiny stated that America was destined by Gods will to expand westward in North America and eventually become a superior nation. A lot of the westward land was controlled by lots of Native American tribes and also Spain. But Americans strongly felt they were always superior and that the westward land was meant for them instead of the people who lived there. The beginning of the idea of Manifest Destiny had one major effect: Racial Inequality, or Racism. Racial superiority towards Native Americans in the past had become an inevitable effect when Americans fully realized and accepted the idea of Manifest Destiny; this belief was also an inevitable but indirect root cause for societal problems such as Social and Gender Inequality in the future.