The citizens of the Baltic Republics (Latvians, Lithuanians, Estonians, Russians, Jews, Germans, the Poles, and the Finns), as well as many other nations of the former USSR experienced serious difficulties and extreme deprivation during communist rule. They suffered from compulsory deportation organized by the NKVD-KGB and the Soviet Ministry of Internal Affairs. One of those initiatives was the so-called "Spring operation" in 1948. Since the mid-1950s, these nations were gradually rehabilitated.The book contains documents and materials from the main archives of the Russian Federation, including the USSR NKVD-KGB and MVD-MGB secret archives. For many years, these documents had been filed under the sections "Top secret" and "Not subject to disclosure." Only recently did they become available for Russian historians.