Why leave your homeland? The many and varied personal reasons can be generalized as:

• “Push” factors (why leave a place) and
• “Pull” factors (why go to a particular place)

One example of a “push factor” is described in this blog about Mecklenburg, a region in the eastern portion of Germany. Between 1820 and 1890, new laws freed the serfs from their land without specifying where they should live. To marry, hold a permanent job, in fact, to do most things, a person had to be “established,” or have a right to live somewhere. But that right had to be granted, and was not easy to obtain. Thousands from Mecklenburg instead exercised their newly granted right to emigrate, some to the USA, others to South America.

So, not permitting newly-freed serfs to register to live somewhere turns out to be a classic “Push” factor.