<human>:  Why did so many Germans emigrate to the United States in the 19th century?
<bot>: That would be the potato famine in Ireland. The potato was the main food source for many Irish families. When the potato crop failed, the Irish people had to eat other foods, like meat, which was expensive. Many Irish people were forced to emigrate to the United States. They found jobs working in the mines and on the railroads, and they settled in cities like New York and Chicago.