Mostly Europeans? Yes. But most were just looking for better jobs, not fleeing from war, persecution and famine. And Ellis Island wasn't just an acceptance point for immigration. Many were rejected for being ill or for their likelihood of becoming wards of the state and sent back home.
Yeah, back then we only accepted people that were not inbred imbeciles or permanently stupid or had communicable deceases. What monsters we were! Oh yeah I almost forgot; We used to insist that they had some sort of skill that would make them a benefit to our society. How sick was that!