Final answer:
Most immigrants to the United States in the mid-1800s came from Ireland and Germany, driven by factors such as the Great Famine and political unrest.
Step-by-step explanation:
In the mid-1800s, the largest groups of immigrants to the United States came from Ireland and Germany. The Irish immigration was largely spurred by the Great Famine of the 1840s, which caused mass starvation and deaths in Ireland. Simultaneously, Germans were emigrating in large numbers due to economic opportunities and to escape from political unrest, such as the aftermath of the Revolutions of 1848. Both groups sought better lives and contributed to the American society, with many Irish settling in urban areas of the Northeast and Germans forming enclaves in the Midwest. As they moved westward, several thousand immigrants established homesteads in states like Minnesota and Wisconsin.