This dissertation investigates the durability of Soviet kinship ties in the midst of the dislocations of the Second World War. It explores how Soviet citizens attempted to locate family members with whom they lost contact and how the Soviet regime responded to the predicament of war-torn Soviet families during and in the aftermath of the conflict. Based on archival materials from Russian, British, and US archives, as well as the International Tracing Service archive, this dissertation reveals that the USSR prioritized reuniting displaced Soviet citizens with Soviet society, rather than with their biological families. While recent scholarship has illustrated that Western and Central European states prioritized reuniting families to rehabilitate war-devastated nations, my work shows that the Kremlin sought to champion a new, Soviet conception of family: one bound by a shared Soviet identity grounded in revolution and war, rather than by blood. By analyzing the politics of reunification for families separated due to military mobilization, evacuation, forced external displacement by Nazi forces, and internal deportation by the Soviet regime, this dissertation reveals that the Kremlin’s response to family separation was shaped by the exigencies of wartime mobilization and postwar reconstruction. When confronted with citizens’ appeals for aid to find lost kin, Soviet authorities endeavored to reunite war-torn families to mobilize the domestic population during the war and convince externally displaced citizens to repatriate after the conflict ended. These efforts helped millions of citizens re-establish contact with their family members. Yet they coexisted with the Soviet regime’s response to the crisis of over half a million wartime orphans: its promotion of the Soviet family as not necessarily bound by blood ties, but by a shared commitment to the Soviet Motherland. By promoting adoption and the establishment of families that were microcosms of the diverse “great Soviet family,” the regime conveyed the notion that an overarching Soviet identity could supersede the biological ties torn asunder during the conflict. Citizens’ dogged efforts to find their lost kin in the decades after the war reveal that this conception of the Soviet family did not take root. Wartime orphans’ persistent efforts to trace surviving family members reveal that many citizens believed that family origins determined their place in overarching Soviet society and that kinship ties were in fact the ties that bind.