Reclaiming citizenship in an EU country. Difficult.

D. and I were discussing last night the possibility of reclaiming heritage from our respective families and their countries of origin. We've been recently enjoying the show on PBS "Finding your Roots" with Dr. Henry Louis Gates Jr., a truly beautiful show which is also very educational at the same time about science and DNA, as well as our country's history and the history of the countries we all came from. It got us talking about what we know, what we want to know, and what we could prove if asked about where we came from. D.'s family mythology suggests Germany, Poland, Lithuania, and possibly Russia. He does have some cousins who have been in Paris since WWII. Mine is mostly Russia (Belarus) and one part which, depending on the year, people did not know what country they lived in because the borders were continually changing due to wars and resulting treaties. So, we began researching whether you can achieve citizenship in an EU country based on heritage and ancestry. I found one comprehensive website with many links that was quite helpful. Looks like possibilities for Lithuania but not from Germany or Poland, as both of D.'s parents were born in US, while grandparents were born there. For my family, it is likely even more difficult to prove as all of my grandparents were born in the US, although some of their siblings were born overseas. http://livingingreece.gr/2008/03/18/how-to-acquire-eu-citizenship-through-ancestry-or-naturalization/ Still, interesting to research the different laws and requirements of each country, as being an EU citizen has so many benefits now to live and to work.