Emigration from the Union of Soviet Socialist Republics (USSR; Soviet Union) was, for most of its history (1917–91), forbidden. Those who did emigrate were often dissidents and came from many, mostly non-Russian ethnic groups, including Jews, Armenians, Estonians, Latvians, Lithuanians, and Ukrainians. There was little or no sense of Soviet identity; the history, social organization, and areas of settlement varied from group to group. As a result of the dissolution of the Soviet Union in 1991, it is usually within the context of the specific ethnic groups that immigration is most meaningfully discussed. The USSR was the largest state the modern world had seen, occupying 8,649,500 square miles, or about 30 percent more territory than modern Russia. It stretched from eastern Europe across northern Asia to the Pacific Ocean. It was bordered on the west by Finland, Norway, Poland, Czechoslovakia, Hungary, and Romania and on the south by Turkey, Iran, Afghanistan, China, Mongolia, and North Korea. At the time of its collapse, there were 15 major ethnic groups in the Soviet Union, forming the basis for the 15 states that emerged. There were many other smaller ethnic groups, as well. During the 18th, 19th, and 20th centuries, the transformation of Russian state boundaries significantly affected the character of Russian immigration. Ivan the Terrible (r. 1533–84), the first czar, began the expansion of the state to include significant numbers of non-Russian peoples. Between 1667 and 1795, Russia expanded westward, conquering lands mainly from the kingdoms of Poland and Sweden that included the peoples of modern Latvia, Lithuania, Estonia, eastern Poland, Belarus, and Ukraine. Russia acquired most of the remainder of Poland and Moldova (Bessarabia) in 1815, following the Napoleonic Wars. Throughout the 19th century, Russia continued to expand, especially into the Caucasus Mountain region and central Asia, occupying regions that would later become the modern countries of Armenia, Azerbaijan, Georgia, Kazakhstan, Kyrgyzstan, Turkmenistan, Tajikistan, and Uzbekistan. During the great age of immigration from eastern Europe between 1880 and 1920, therefore, more than a dozen major ethnic groups might be classified by immigration agents as “Russian,” though they were in fact part of these older nations. The Bolshevik Revolution of 1917, which ushered in the world’s first communist government, soon spread to most of the surrounding territories acquired by Russia, leading to the establishment of the USSR in 1922. The USSR consisted roughly of the old Russian Empire, except for the loss of Finland, Latvia, Estonia, Lithuania, and Poland, which became independent countries after World War I (1914–18). During World War II (1939–45), the Soviet Union reoccupied parts of Finland, Estonia, Latvia, Lithuania, Poland, and Moldova and afterward exercised extensive control over the foreign and immigration policies of the nominally independent countries of Poland, Czechoslovakia, Hungary, East Germany, and Romania. Finally, in 1991, the Soviet Union collapsed. In its place were 15 separate states, each having its own annual immigration quota to the United States and Canada. The Soviet government tightly controlled emigration. Most who did emigrate were wartime refugees, who were not allowed to return, or were Jews, who were sporadically allowed to leave legally from 1970. Whereas an average of about 125,000 immigrants came to the United States annually from the old Russian Empire between 1901 and 1920, the figure dropped to only about 6,100 during the 1920s, with most of these being anticommunist, White Russians who fled in the immediate wake of the Russian Civil War, prior to the formal establishment of the USSR (1922). The Soviet government then banned virtually all emigration, and those who did come to the United States and Canada were often viewed with suspicion, in part because of their radical ideas and labor union involvement: Between 1931 and 1970, only about 5,000 Soviets immigrated, many of them dissidents and not all Russians. The United States accepted about 20,000 Soviet refugees under provisions of the Displaced Persons Act of 1948 and related executive measures after World War II. About 40 percent of Canada’s 125,000 refugee immigrants between 1947 and 1953 were Ukrainians (16 percent), Jews (10 percent), Lithuanians (6 percent), Latvians (6 percent), and Russians (3 percent), most of whom came from Soviet lands. As cold war tensions eased during the 1970s, the Soviet government gradually relaxed emigration restrictions, which led to an annual average immigration to the United States of about 4,800 between 1970 and 1990, mostly Jews and Armenians. It is estimated that between 1970 and 1985, about a quarter million Jews were allowed to emigrate, often as a part of Western diplomatic efforts to secure better treatment for them. Most went to Israel, but perhaps 100,000 settled in the United States. With the final collapse of the Soviet Union in 1991, a massive exodus from the economically debilitated country ensued. Almost a half million Soviets or former Soviets immigrated to the United States during the 1990s, probably about 15 percent of them ethnic Russians. The substantial immigration continued into the following decade, with about 55,000 coming in both 2001 and 2002. Of Canada’s 142,000 immigrants from the former Soviet Union (2001), 53 percent came between 1991 and 2001. See also Armenian immigration; Estonian immigration; Jewish immigration; Latvian immigration; Lithuanian immigration; Ukrainian immigration.