Killed an entire continent of peoples and enslaved millions of people from another one to make agricultural commodities.

Why do you only mention the Jewish people and not the Roma, the homosexual, the transgender, the socialist, the communist or the many other groups targeted? Far more than 6 million were targets of genocide by the Nazis.

https://en.wikipedia.org/wiki/Native_American_genocide_in_the_United_States - 4+ million Native Americans killed in a time when overall populations where much lower. If that number were scaled to the 20th century population it would be an order of magnitude higher.

At once, in a assembly way or specifically targeting Jewish people?

Plus it’s not like they were cool with those trying to escape Germany. And chance would have sided with Germany if Britain had fallen.

https://www.pbs.org/wnet/exploring-hate/2022/03/14/today-in-history-antisemitism-an-american-problem/