Question: when did the country Saldus Municipality is located become part of the Soviet Union?

full_context: Document 1: Post-Soviet states: The post-Soviet states, also collectively known as the former Soviet Union (FSU) or former Soviet Republics, are the 15 independent states that emerged from the Union of Soviet Socialist Republics in its dissolution in December 1991, with Russia internationally recognised as the successor state to the Soviet Union. On March 11, 1990, Lithuania was the first to declare its independence, with Estonia and Latvia following suit in August 1991. All three Baltic states claimed continuity from the original states that existed prior to their annexation by the Soviet Union in 1944 and were admitted to the United Nations on 17 September 1991. The remaining 12 republics all subsequently seceded. 12 of the 15 states, excluding the Baltic states, initially formed the CIS and most joined CSTO, while the Baltic states focused on European Union and NATO membership.
Document 2: Frédéric Chopin: In 1817 the Saxon Palace was requisitioned by Warsaw's Russian governor for military use, and the Warsaw Lyceum was reestablished in the Kazimierz Palace (today the rectorate of Warsaw University). Fryderyk and his family moved to a building, which still survives, adjacent to the Kazimierz Palace. During this period, Fryderyk was sometimes invited to the Belweder Palace as playmate to the son of the ruler of Russian Poland, Grand Duke Constantine; he played the piano for the Duke and composed a march for him. Julian Ursyn Niemcewicz, in his dramatic eclogue, "Nasze Przebiegi" ("Our Discourses", 1818), attested to "little Chopin's" popularity.
Document 3: Molotov–Ribbentrop Pact: In mid-June 1940, when international attention was focused on the German invasion of France, Soviet NKVD troops raided border posts in Lithuania, Estonia and Latvia. State administrations were liquidated and replaced by Soviet cadres, in which 34,250 Latvians, 75,000 Lithuanians and almost 60,000 Estonians were deported or killed. Elections were held with single pro-Soviet candidates listed for many positions, with resulting peoples assemblies immediately requesting admission into the USSR, which was granted by the Soviet Union. The USSR annexed the whole of Lithuania, including the Scheschupe area, which was to be given to Germany.
Document 4: Estonia: In 1989, during the "Singing Revolution", in a landmark demonstration for more independence, more than two million people formed a human chain stretching through Lithuania, Latvia and Estonia, called the Baltic Way. All three nations had similar experiences of occupation and similar aspirations for regaining independence. The Estonian Sovereignty Declaration was issued on 16 November 1988. On 20 August 1991, Estonia declared formal independence during the Soviet military coup attempt in Moscow, reconstituting the pre-1940 state. The Soviet Union recognised the independence of Estonia on 6 September 1991. The first country to diplomatically recognise Estonia's reclaimed independence was Iceland. The last units of the Russian army left on 31 August 1994.
Document 5: History of Latvia: The First Latvian National Awakening began in the 1850s and continued to bear fruit after World War I when, after two years of struggle in the Latvian War of Independence, Latvia finally won sovereign independence, as recognised by Soviet Russia in 1920 and by the international community in 1921. The Constitution of Latvia was adopted in 1922. Political instability and effects of the Great Depression led to the May 15, 1934 coup d'état by Prime Minister Kārlis Ulmanis. Latvia's independence was interrupted in June -- July 1940, when the country was occupied and incorporated into the Soviet Union. In 1941 it was invaded and occupied by Nazi Germany, then reconquered by the Soviets in 1944 -- 45.
Document 6: Mathias Spieler: In the latter half of the 17th century, Marshal of the Realm of Sweden Johan Gabriel Stenbock (1640-1705) brought the Sjööe state in the parish of Holm in Enköping. Together with Mathias Spieler and architect Nicodemus Tessin the Elder (1615-1681), Stenbock built Sjöö Castle on his estate. The construction work lasted from 1669 until 1679 resulting in the shape and form in which it is today. Sjöö Castle Palace with its park is considered one of the most beautiful in Sweden, with its perfect and harmonious proportions.
Document 7: Jumurda Manor: Jumurda Manor () is a manor house in the historical region of Vidzeme, in northern Latvia. It was built after 1856 in Eclectic style. Vandalized during the Revolution of 1905, the manor was restored in 1907. After 1929 it housed the Jumurda primary school for many years. The estate buildings and manor house are gradually being renovated to create a resort hotel complex.
Document 8: Dissolution of the Soviet Union: On June 14, 1987, about 5,000 people gathered again at Freedom Monument in Riga, and laid flowers to commemorate the anniversary of Stalin's mass deportation of Latvians in 1941. This was the first large demonstration in the Baltic republics to commemorate the anniversary of an event contrary to official Soviet history. The authorities did not crack down on demonstrators, which encouraged more and larger demonstrations throughout the Baltic States. The next major anniversary after the August 23 Molotov Pact demonstration was on November 18, the date of Latvia’s independence in 1918. On November 18, 1987, hundreds of police and civilian militiamen cordoned off the central square to prevent any demonstration at Freedom Monument, but thousands lined the streets of Riga in silent protest regardless.
Document 9: Jaunauce Manor: Jaunauce Manor (; ) is a manor house in Jaunauce parish in Saldus municipality in the historical region of Courland, in western Latvia. It was built in the early 19th century for Count Karl Johann Friedrich von Medem, who bequeathed the estate to his daughter Caroline and her husband Ferdinand von der Ropp in 1827. It belonged to the von der Ropp family until the agrarian reform in 1920. The building has housed the Jaunauce primary school since 1931. Jaunace Manor is one of the best preserved examples of late classicism architecture in Latvia.
Document 10: Latvian Soviet Socialist Republic: Following the Welles Declaration of July 23, 1940, the annexation of Latvia into the Soviet Union (USSR) on 5 August 1940 was not recognized as legitimate by the United States, the European Community, and recognition of it as the nominal fifteenth constituent republic of the USSR was withheld for five decades. Its territory was subsequently conquered by Nazi Germany in June -- July 1941, before being retaken by the Soviets in 1944 -- 1945. Nevertheless, Latvia continued to exist as a de jure independent country with a number of countries continued to recognize Latvian diplomats and consuls who still functioned in the name of their former governments.
Document 11: Estonia: On 6 August 1940, Estonia was annexed by the Soviet Union as the Estonian SSR. The provisions in the Estonian constitution requiring a popular referendum to decide on joining a supra-national body were ignored. Instead the vote to join the Soviet Union was taken by those elected in the elections held the previous month. Additionally those who had failed to do their "political duty" of voting Estonia into the USSR, specifically those who had failed to have their passports stamped for voting, were condemned to death by Soviet tribunals. The repressions followed with the mass deportations carried out by the Soviets in Estonia on 14 June 1941. Many of the country's political and intellectual leaders were killed or deported to remote areas of the USSR by the Soviet authorities in 1940–1941. Repressive actions were also taken against thousands of ordinary people.
Document 12: Lithuanian Soviet Socialist Republic: The Lithuanian Soviet Socialist Republic (Lithuanian SSR; Lithuanian: Lietuvos Tarybų Socialistinė Respublika; Russian: Литовская Советская Социалистическая Республика, Litovskaya Sovetskaya Sotsialisticheskaya Respublika), also known as Soviet Lithuania or Lithuania was a republic of the Soviet Union. It existed from 1940 to 1990.
Document 13: Zvārtava Manor: Zvārtava Manor (; ) is a manor house in the historical region of Vidzeme, northern Latvia. It was built in 1881 in Tudor Neo-Gothic style.
Document 14: Baldone Manor: Baldone Manor, also called Baldone White Palace, is a manor house in the historical region of Zemgale, in Latvia. It was built in 1901 as a hunting lodge.
Document 15: Ungurmuiža Manor: Ungurmuiža Manor (, ) is a manor house in the historical region of Vidzeme, in northern Latvia. The estate is named for the von Ungern family, who owned it prior to the middle of the 17th century. The current wooden manor was built in 1731-1732 in Baroque style for the owner, Lieutenant General Balthasar Freiherr von Campenhausen. The von Campenhausen family owned the estate from 1728 to 1939. Ungurmuiža manor was one of those manors which was not nationalised in Latvian agrarian reforms of the 1920s. Despite its quite small size, manor is elegant construction with richest wall paintings and ceiling plafonds of Baroque age in Vidzeme region.
ground_truth: 5 August 1940
sub_queries: Saldus Municipality >> country Answer: Latvia
when did Latvia become part of the soviet union Answer: 5 August 1940