What was a major concern of scientists who left Nazi Germany for the United States before World War II?

Back in the day they used those stuff to make weapons and they put them in ships because there's a gate and you have to pay to get throw and they cheek to see if theres any thing in there on a ship they can t look at all because it counts as privet property so that's how in civil war the men in north America got stuff to the south for the women AND children to make weapons for war. the plan was to sneak metal in the ships and bring it to the south for the women and to make weapons for the military and that was in Germany