Assuming you mean America, the 1840s due to the potato famine.
Because they were falsely led to believe that American is the most free country in the world.
They wanted to find a job and have peace
Ireland
At the time when most people were immigrating to America - particularly Ellis Island - the cost of travel was a lot. This is mostly down to the cost of power and fuel in the boats used to ship immigrants to this region of America. £10 was the average cost to immigrate.
to find jobs
Some Scottish immigrants to America were forced there as convicted prisoners, but most came seeking an opportunity for a better life, as did most other immigrants to America.
Most of them came from Nazi Germany between 1933 and 1939. Those were German Jews.
New York City
Professionals in search of better opportunities and better pay are the most likely to immigrate. Also, skilled laborers may immigrate.
The same reason most people immigrate to the US: to have a better life and escape the bad conditions in their homeland.
Germany