He's 20th century -- at least his main body of work. A guy who invented a number of things you most certainly heard of too. And a curious death to boot.
Yeah, I don't understand how they figure these out. Some of the "pictures" aren't even real pics, but rather drawings. I've only figured out probably one yet.
It's often not at all about the photos, but about the photo + the clues.
And what's cool about this thread is that we generally pick up interesting personalities that just aren't covered in popular media. And they often give you an example of someone worth reading up on -- in a "why didn't I know about him?" way.
OK, here's another hint. This guy was considered quite a prodigious inventor at the time. But in modern times, his inventions have taken on a, well, a much more controversial tone.