Final answer:
Europeans migrated to the U.S. between 1880 and 1920 mainly for economic opportunities provided by industrial growth and to escape poverty, religious persecution, and political strife in their home countries.
Step-by-step explanation:
Between the years of 1880 and 1920, the primary reasons for European migration to the United States were related to economic opportunities and escaping various hardships. Massive industrial growth in America provided a plethora of job opportunities in factories, mines, and the construction of the transcontinental railroad, attracting many to the new world. Additionally, there were also significant numbers of people fleeing from poverty, religious persecution (e.g., Jews facing pogroms in the Russian Empire), political turmoil, and the impacts of industrialization in their home countries.
This period, often referred to as the Great Wave of immigration, saw people leaving overcrowded and economically stagnant regions in Europe, such as southern Italy, Sicily, and parts of eastern Europe. The U.S. served as an appealing destination due to its promise of work and the chance at a better life, epitomized by the notion of the American Dream. In addition to economic factors, the immigrations served as a 'safety valve' for European countries that had an excess of landless peasants and sought to relieve social pressures.