The single policy adopted by James Monroe in 1823 is called the Monroe Doctrine and serves as a symbol of early American nationalisms. In Document A, the Monroe Doctrine is demonstrated by an invisible border that separates the Western Hemisphere from the Eastern Hemisphere and a stop sign on the Western side. The European region says: “What do you mean “off-limits?” ", which shows to what extent she does not approve of the doctrine which prevents her from hindering the expansion of the United States on the Western side. In document B, two flower pots illustrate nationalism. A flower pot smiles and declares: “Wow! I'm so glad I was born in this pot and not that one! ", even if the other looks mediocre. Given this, at this early stage of the creation of the United States, other states, especially European countries, cannot be trusted not to try to steal their “rightfully rightful land.” This document offered the only option at the time: placing an invisible border to prevent other countries from hindering America's expansion and security. Furthermore, the convention stipulated that the New World and the Old World were to remain indisputably isolated. Congress, like James Monroe, knew that this doctrine would not make sense in the eyes of Europe and the rest of the world; However, this did not stop citizens of the Americas from creating a sense of nationalism based on a false perception of security that the government gave them. It was a period of transition, from 1817 to 1825, during which the country's legal foundations and industrial economy were taking shape, as Document F shows. According to Document G, "During this period, a industrial revolution was starting in the North… The status of America as a whole was reinforced. " However, in Document H, "the separation of the issue of slavery (used to meet the growing needs of cotton plantations in the South) would exist in America from this time until the Civil War. " Furthermore, with virtually no ill effect, nationalism manifested itself after the inauguration of the Monroe Doctrine in the way Americans no longer referred to themselves as "Rhode Islanders" or "Rhode Islanders". ».