Article: On January 21, 1990, Rukh organized a 300-mile (480 km) human chain between Kiev, Lviv, and Ivano-Frankivsk. Hundreds of thousands joined hands to commemorate the proclamation of Ukrainian independence in 1918 and the reunification of Ukrainian lands one year later (1919 Unification Act). On January 23, 1990, the Ukrainian Greek-Catholic Church held its first synod since its liquidation by the Soviets in 1946 (an act which the gathering declared invalid). On February 9, 1990, the Ukrainian Ministry of Justice officially registered Rukh. However, the registration came too late for Rukh to stand its own candidates for the parliamentary and local elections on March 4. At the 1990 elections of people's deputies to the Supreme Council (Verkhovna Rada), candidates from the Democratic Bloc won landslide victories in western Ukrainian oblasts. A majority of the seats had to hold run-off elections. On March 18, Democratic candidates scored further victories in the run-offs. The Democratic Bloc gained about 90 out of 450 seats in the new parliament.

Question: What country's independence were the chain members celebrating?
Ukrainian