Einstein primarily emigrated to the United States because he had a Jewish background, and Adolf Hitler, who became Germany's chancellor in 1932, was about to adopt Anti-Semitic policies.
It was a very hard choice for Einstein to choose to emigrate to the United States, but it was a very wise one. As a Jew, he knew what was gonna happen if he stayed in the United States. You may already know that the Holocaust happened a few years later, in which most Jews living in countries occupied by Germany were murdered. Thanks to moving to the U.S, Einstein was safe from this event.
The United States claimed the Lusitania carried an innocent cargo, and therefore the torpedoing was a monstrous German atrocity. Actually, the Lusitania was heavily armed: it carried 1,248 cases of 3 inch shells, 4,927 boxes of cartridges (1,000 rounds in each box), and 2,000 more cases of small arms ammunition. The British and American governments lied about the cargo.
