Following one of the largest displacements in human history, almost eight million forced migrants arrived in West Germany after WWII. We study empirically how the settlement location of migrants affected their economic, social and political integration in West Germany. We first document large differences in integration outcomes across West German counties. We then show that high inflows of migrants and a large agrarian base hampered integration. Religious differences between migrants and natives had no effect on economic integration. Yet, they decreased intermarriage rates and strengthened anti-migrant parties. Based on our estimates, we simulate the regional distribution of migrants that maximizes their labor force participation. Inner-German migration in the 1950s brought the actual distribution closer to its optimum.