I was searching Luxembourg genealogy on Google this morning and stumbled across one of Amy's old posts reviewing a surname frequency app (http://wetree.blogspot.com/2009/02/were-big-in-luxembourg.html). What struck me wasn't the surname frequency (my family has the same stats!), but how few of us know about the Luxembourg population in North Dakota!
Several branches of my family made their way to North Dakota. They were driven by access to homestead land as well as the westward growth of the railroad, c. 1870. They built lives there. Some stayed; others moved onto the next frontier - Canada and the American West. They were only one of several families referenced in Luxembourgers in the New World.
For more information, you may want to look at Luxembourgers in the New World and North Dakota Immigrants: Coming to America. I suspect there are more resources. What have you heard about?