The biblical Exodus was the escape of the Israelites from slavery in Egypt. The Exodus inspired William Wilberforce's fight to outlaw slavery in England. Wilberforce was fighting a cultural war, that he had little hope of winning but he persevered.
World War II was beyond all doubt a war against oppression, that did not go well at the start (all of Europe except for Russia, Spain, Portugal, and the British Isles was under Nazi control by Spring 1941). Even though the war seemed hopeless by that point, the British, Soviets, and undergrounds in occupied territories continued to resist the Nazis until The tide turned in the winter of '43-44.
The Cold War was perceived by some to be against oppression of Godless Communism.
Many of the "Socialist" revolutions (e.g. the French Revolution) were against the economic "oppression" of the rich and powerful. These are but some of the incidents he is probably talking about.