The article examines the case of the mass emigration of Germans from the Soviet Union to Europe and America in the late 1920s, referred to as the “American fever”. Based on unpublished archival materials from the collections of RGASPI (Russian State Archive of Social-Political History) and GARF (State Archive of the Russian Federation), as well as documentary collections, German periodicals of the era, and contemporary research, the study presents a comprehensive account of the alterations in the conditions of departure from the USSR for Soviet citizens of German nationality, encompassing both reunification with relatives and resettlement for permanent residence in Germany, Canada, and other countries. Throughout the first half of the 1920s, Germans were granted relatively unrestricted travel as a means of eliminating “internal enemies” and “declassified elements”. Later, the Soviet government made decisions to restrict and ultimately prohibit mass emigration from the USSR. The underlying factors and reasons for the expulsion of the German-speaking Mennonite community from the USSR, which possessed a prominent anti-Bolshevik stance, and the subsequent prohibitions on their emigration are scrutinized. The primary factors that sparked emigration sentiments in the German countryside were collectivization, the struggle against religion, hunger, and oppression. The aforementioned “American fever” garnered significant international attention and resonance in the Western media. In response, the Soviet leadership implemented “preventative measures” to eradicate the emigration movement. A flurry of raids, arrests and repression swept through German villages and the Sovietization of the German countryside intensified. German peasants who had gathered near Moscow were forcibly evicted back. Only 5,671 German nationals were able to leave the USSR, while most of the emigrants were forcibly returned, and all of them were placed under supervision, or detained by the OGPU. The Soviet government was unprepared for mass emigration from the USSR as a non-violent form of resistance. The mass nature of the emigration movement as well as the appeal of the Germans to a foreign state, in this case to Germany, for help, clearly showed the Bolshevik government a low degree of loyalty, both of the refugees themselves and their local supporters.