I am speaking from memory but I think you will find that although the American Army penetrated deep into Eastern Germany and Czechoslovakia at the end of WW2, (I am pretty sure they liberated Prague), I am also pretty sure all the Allies had withdrawn to the main zones of occupation, American Zone SW Germany, in about three months. Yalta Agreement? It is unlikely that your father was ever "stationed" in Czechoslovakia, the Americans just went in and out again. Of course this does not mean he did not have time to father a child, but if, as seems, you are talking about a relationship of more than a one-night stand I think you might do better to concentrate on the American Zone of Occupation, I think Wiesbaden was the HQ, but do remember the Germans were starving, the occupying armies had food and many friendships were based on the possibility of getting something for them and their families to eat. There were thousands of "Besatzungskinder" (occupation children) probably the majority of whom did not know/were never told who their fathers were. Best of luck anyway.