Let's be clear about the difference between taking the photograph and publishing the photograph. Since the Ellis Island display is in a public place where everyone's allowed to go, Bloke has every right to shoot his photograph. But publishing it could be a different matter.
On the other hand, even if the pictures he included in his picture are copyrighted he's probably off the hook unless they were registered with the copyright office. To cause Bloke a problem the copyright holder probably would have to show monetary damage by Bloke's publication of his picture. Furthermore, unless some of the pictures were added after Ellis Island closed in 1954, the copyrights probably have expired. That's a guess. I'd have to go back into the copyright info on some of my early pictures to be sure, but copyright laws were very different back in those days.
But as a photographer Bloke needs to be careful and learn something about copyright laws. Pop's right: you can get badly burned by publishing copyrighted material, even inadvertently. There's an interesting article in that vein in the current Digital Photo Pro mag. By the way, the idea that the absence of a copyright notice sets you free is a holdover from earlier times when the notice was essential. Not true any more.