Immigration is the act of coming to live in a foreign country. The act of leaving the country of origin is called emigration. Over the years of human development, the processes of immigration-emigration (migration) have constituted an important part of social life, so they have never stopped, while the foci of migration have changed. After Columbus discovered America in 1492, it became one of the most popular destinations for emigration. The first newcomers were settlers looking for the gold pyramids of the Indians, then in America strangers found their home. According to the United Nations website, the United States of America, a country made up of 13 colonies, now ranks first in foreign-born population (2013). It is worth noting that immigration to the United States has not always been constant. Historians distinguish four periods in which the rate of immigration was enormous, the so-called "waves". The first wave continued until 1775, the second wave began in 1820 and ended in 1870, the third massive influx of immigrants faced by the United States was from 1880 to 1920, and the last one to date began in 1965. The third wave is considered the largest and is of particular interest to study. According to some sources, it is considered one of the largest migrations in the history of the world, therefore it had significant repercussions on the internal and external policies of the United States. Nowadays it is believed that America is filled with a large number of Latin American immigrants who come to the state legally or not. Factory working conditions for the lower classes in Europe in the late 19th century were unfair. Child labor, 12-hour shifts, and life in shacks were quite common throughout Europe. The northern part suffered from the lack of fertile lands, half of the population of American origin, composed mainly of children and grandchildren of other street immigrants and the government, influenced by racism, propaganda, lack of education and imperfection of the legal system that could not serve the interests of all people living in the United States, regardless of their ethnic group and homeland. Under double pressure, third wave immigrants managed to adapt to new living conditions and even change attitudes towards men from both the Old and New Worlds. The newcomers helped transform American society and culture, demonstrating that diversity, as well as unity, is a source of national strength. On the eastern side, immigrants left Europe with virtually no labor force, no war force, but they gave the opportunity to refresh society and build new countries for the people, not for the government itself..