German emigrants came to the United States for different reasons. Some were peasants and artisans, hoping for more economic opportunities. Others were political dissidents, searching for freedom from the tyranny in parts of Germany or escaping failed attempts at revolution. In the wake of unsuccessful agitations for democracy in Germany in 1848, many German political liberals fled to the United States. Most Germans settled in the cities and on farms in the Midwest.

Like the English, Irish and Scotch-Irish; Germans had been settling in North America since before the Revolutionary War, but the flow of immigration increased in the period from 1830 to 1890. Unlike the Irish, however, they came from different socio-economic groups and religious backgrounds, including Roman Catholic, Lutheran, Reformed (Protestant), Jewish and anti-clerical or free-thinkers. Thus, they were harder to stereotype than the Irish, although their accents and their attempts to maintain German as their daily language aroused some prejudice and resentment from other Americans. Although German Americans faced discrimination, they were able to assimilate into mainstream American culture with less difficulty than the Irish. By 1900, Germans and German Americans made up the largest single foreign group in several states, including Wisconsin, California, Kansas, Missouri, New Jersey and New York. They made a major impact on American society, especially with their Christmas traditions.

German Americans played a significant role in the Civil War. Many German Americans, especially those with liberal political views, abhorred the institution of slavery. August Bondi, a German-born abolitionist, fought with famous abolitionist John Brown during the Missouri-Kansas border wars. In addition, most German immigrants, like most other immigrants, settled in the pro-Union free states of the North and Northwest. While American-born German Americans, such as Samuel Peter Heinzelman, fought in the Civil War, recent immigrants were also very active in the Union effort. Those German Americans in the South, however, tended to agree with the prevalent pro-slavery, pro-secession sentiments of many of their white American neighbors.

Early in 1861, newly-arrived German immigrants were one of the largest groups to form volunteer units. Many of these troops and officers had obtained fighting experience in Europe. Two of the most prominent people organizing these troops were Louis Blenker and Julius Stahel. Blenker had led troops in the German revolution of 1848, while Stahel had fought in the unsuccessful bid for Hungarian independence from Germany. The two men recruited troops for the 1st German Rifles (8th New York regiment). Blenker led a German brigade at the First Battle of Bull Run in 1861. By October of 1861, the War Department organized several German regiments into "Blenker's Division." As with Irish Americans, the patriotic participation of German Americans helped ease their acceptance into mainstream culture.