Ukrainians have the memory of many key events of the 20th century, the importance and timeliness which do not weaken over time, given the increasing need to study the experience of their ancestors in the fight for freedom, independence and the construction of the national state. From this point of view January 22, 1919, will remain etched in their memory as a date of proclamation of the Reunification Act of the Ukrainian People's Republic (UPR) with the Western Ukrainian People's Republic (WUPR), which explains the inclusion in the modern Ukrainian calendar of such solemn event as the Day of Reunion.
It was a day of the decision that was made to unite the Ukrainian people, divided by history. Thus, the unified and unitary state based on the age-old dream and the willingness, widely shared by both sides of the Ukrainian nation, emerged.
Yet this historic opportunity could not be fully exploited at that time. The merger could not be completed due to internal and external extremely complicated situation. Again, for several decades Ukraine had found stripped of its sovereignty.
The Reunification Act provided outline of the independent Ukrainian state. Even today, the union of UPR and WUPR appears as civilized, democratic and non-expansionist model of territorial integration in a single sovereign state. This unifying action of 1919 has left deep traces in the historical consciousness of the Ukrainian people. In 1990 it gave force to patriotic Ukrainians to come together in a long living chain of several hundred kilometers from Lviv, the major city in the west of the country, to Kyiv, the capital of Ukraine.
The essential characteristic feature of the Reunion is summarized in the full merger of national territories, their spiritual and cultural consolidation, eliminating regional barriers. The unity of the Ukrainian state is preserved in the Constitution of Ukraine and its territorial integrity remains a key factor of its sovereignty.