Unfortunately, I have no idea about schools and colleges in the US teaching Germanic linguistics with a historical emphasis. But if you ever decide to study a year abroad, you should consider a to go to the Ludwig-Maximilians-Universität in Munich/Germany (English version. They do have a (in German) with an historical emphasis as well as a dept. for Germanic linguistics (in German) where Prof. Theo Vennemann PhD (in English - private homepage in German) is teaching theroretical as well as historical linguistics - see his homepage for publications.

Hope that helps a little bit - wishing you luck wirh your efforts!