Currently, the strongest branch of America's government is the Executive branch.
While the branches were once co-equal, the Presidency has taken on a life of its own with the ability to wage war without Congressional approval and to dictate the terms to Congress without much push back.
Correct answer: World War II Europe.
The references to "fighting the Germans when Poland had first been invaded" identify this narrative as happening during World War II in Europe. Other nations in Europe, notably Britain and France, had followed a policy of appeasement toward Adolph Hitler and Germany's efforts to add territory to its control. They allowed Germany to annex the Sudentland, and then did nothing when Germany took control of all of Czechoslovakia (in March, 1939). But when Germany invaded Poland in September, 1939, it was beyond clear that appeasing Hitler hadn't worked, and war was pursued. Germany's invasion of Poland was the beginning of World War II in Europe.
Answer:
It was in this environment, seeing the possibility of an America where black and white citizens were truly equal