You will be given a definition of a task first, then an example. Follow the example to solve a new instance of the task.
In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

what is the first event mentioned?, Context: The Russian Revolution is the series of revolutions in Russia in 1917, which destroyed the Tsarist autocracy and led to the creation of the Soviet Union. Following the abdication of Nicholas II of Russia, the Russian Provisional Government was established. In October 1917, a red faction revolution occurred in which the Red Guard, armed groups of workers and deserting soldiers directed by the Bolshevik Party, seized control of Saint Petersburg (then known as Petrograd) and began an immediate armed takeover of cities and villages throughout the former Russian Empire.
Solution: Russian Revolution
Why? This is a good example, and the Russian Revolution is the first event mentioned.

New input: What made something that was unknown known?, Context: The FBI also spied upon and collected information on Puerto Rican independence leader Pedro Albizu Campos and his Nationalist political party in the 1930s. Abizu Campos was convicted three times in connection with deadly attacks on US government officials: in 1937 (Conspiracy to overthrow the government of the United States), in 1950 (attempted murder), and in 1954 (after an armed assault on the US House of Representatives while in session; although not present, Abizu Campos was considered the mastermind). The FBI operation was covert and did not become known until U.S. Congressman Luis Gutierrez had it made public via the Freedom of Information Act in the 1980s.
Solution:
Freedom of Information Act