Do you have a German immigrant ancestor whom you have absolutely no idea where in Germany they came from? Most of us do. One great method for finding clues on where they might have come from is to use the modern-day German phone book, which is available online at: http://www.dastelefonbuch.de/
Here’s how it works. If the German surname is uncommon enough, you can look for where within Germany the surname seems to be concentrated today. Names like “Schmidt” or “Mueller” or “Meyer” are going to be too common to pinpoint with this method, but if you have German ancestors with rarer surnames like “Bödege” or “Tascher” or “Kerzell”, this method can be effective.
To use dastelefonbuch.de, input the surname you are searching for in the “Wer/Was” (“who/what”) input field, and then hit the “Finden” button. You will be given a list of all the people in Germany with that surname, and you may see some concentrations of that surname in certain areas. If you already have an idea where in Germany your ancestor was from, but you’re not completely certain, you can also add a town name to the “Wo” (“where”) input field, and see if people with that surname do show up in your suspected town.
Keep in mind that after the Industrial Revolution and the world wars, many Germans moved away from the small villages where their ancestors had lived for hundred of years and relocated to larger cities like Hamburg or Bremen or Essen. However, if you find a handful of Germans with your surname of interest, living in a small village somewhere, it could be that these are the remnants of the family that remained in the original ancestral hometown–that hometown might be where your ancestor was from. If you are proficient in the German language, you can even use the “Telefon Buch” records to write a letter to the German individuals with that surname to ask them what they know about their ancestry. You might find a long lost cousin, this way.
If you can use the German telephone book records to pinpoint a town or an area in Germany where people with your desired surname seem to be concentrated, you can then pursue other avenues of research to try to find out if that is in fact where your German ancestor is from. You can contact a state archive or regional church district archive and ask them to conduct a search for your ancestor in that town (for a reasonable fee, of course).