Final answer:
Immigrants came to the United States in the late 1800s and early 1900s primarily for economic opportunity, attracted by the burgeoning industrial economy and the promise of the American Dream.
Step-by-step explanation:
The main reason immigrants came to the United States in the late 1800s and early 1900s was the hope for economic opportunity and the chance to make a better life for themselves and their families. This period witnessed a significant rise in immigration due to the need for labor in the growing industries, such as the building of the transcontinental railroad, and the pull of what came to be known as the American Dream. Immigrants were often fleeing poverty, religious persecution, political unrest, and the impacts of industrialization from their countries of origin.
They came to the U.S. seeking work in its burgeoning economy, especially in industry and agriculture, and joined communities where they could maintain their cultural identities while pursuing economic advancement. Many immigrants believed that through hard work and determination, they could achieve upward mobility and financial success, no matter their background. This was the compelling narrative that drew millions to the United States.