Question

Which was the first of the Baltic states to be occupied, and then absorbed as a constituent republic, by the Union of Soviet Socialist Republics (USSR)?

Answer 1

Lithuania
Lithuania surrendered to an ultimatum by the USSR on 14 June 1940, and then was completely occupied. The USSR issued the same demands to Latvia and Estonia on the following day and similarly occupied those countries. In 1990, on 11 March, Lithuania was also the first of the Soviet-occupied republics to declare independence, a year before formal break-up of the USSR.