The social turmoil of Europe in the 19th century also sent many intellectuals and scholars to the United States. In particular, supporters of the German Revolution of 1848--sometimes called "Forty-Eighters"--brought their tradition of vigorous public debate and social activism to bear on the issues facing the U.S., including land reform, abolition, workers' rights, and women's suffrage. The student radical Carl Schurz, for example, escaped from Germany after the Revolution and settled in Wisconsin. In the course of a long public life, Schurz served his new country as a farmer, a lawyer, a journalist, a campaigner for Abraham Lincoln's Republican Party, a Union general, a cabinet official, a U.S. senator, an early member of the conservation movement, and the founder and editor of several newspapers, in both English and German.
However far they spread, though, and however diverse their ways of life might have been, Germans were still connected by the great web of German-language culture. German newspapers were available in most American cities, from California to Texas to Massachusetts, and German-language traveling speakers, theatrical performers, and popular songs all helped keep German Americans in touch with their cultural heritage.
http://memory.loc.gov/learn/features/immig/alt/german6.html that is their immigration patterns..
Heavy German immigration to the United States occurred between 1848 and World War I, during which time nearly six million Germans immigrated to the United States. From 1840 to 1880 they were the largest group of immigrants. Following the revolutions in German states in 1848, a wave of political refugees fled to America, and became known as Forty-Eighters. They included professionals, journalists, and politicians. Prominent names included Carl Schurz and Henry Villard.[27]
[edit] Cities
The cities of Milwaukee, Chicago, and New York were favored destinations. By 1900, the populations of the cities of Cleveland, Milwaukee, Hoboken and Cincinnati were all more than 40?erman American. Dubuque and Davenport, Iowa, had even larger proportions, as did Omaha, Nebraska, where the proportion of German Americans was 57?n 1910. The Over-the-Rhine neighborhood in Cincinnati was one of the largest German Catholic-American centers.
In the mid 1800s, German immigrants and German Americans increased rapidly in numbers in Milwaukee, known as "the German Athens". When they entered city politics in great numbers, they became a vanguard among that city's Social Democratic Party (Socialists). They were heavily engaged in growing industries. Germans created the beer brewing industry under the Pabst, Schlitz, Miller, and Blatz family brands. German Americans in Milwaukee also brought their strong support of education, establishing schools and teacher training seminaries (Töchter-Institut) to prepare students and teachers in proper German language training. By the late 19th century, the Germania Publishing Company was established, a publisher of books, magazines, and newspapers in German.[28] In many other cities, such as Fort Wayne, Indiana, and Richmond, Virginia, German Americans were at least 30?f the population.
About half went to cities, the other half went to farms in the Midwest.Texas attracted many Germans who entered through Galveston, both those who came to farm and later immigrants who more rapidly took industrial jobs in cities such as Houston. As in Milwaukee, Germans in Houston built the brewing industry. By the 1920s, the first generation of college-educated German Americans were moving into the chemical and oil industries.
Germans also settled in cities in border states, such as Baltimore, Louisville and St. Louis. Few Germans went to the Deep South, though German Americans moving from surrounding rural areas made up a noteworthy part of the population of New Orleans.[29
Wiki pedia
They basically had several spikes of mass immigration most notably during wwi and mid 1800s because of the ties with the brits the usa americans were most prejudiced towards germans at that time. Though many were accepted they were cheap labor for the mines.