World War II: Cologne is captured by American troops. On the same day, Operation Spring Awakening, the last major German offensive of the war, begins.

Cologne is the fourth-most populous city of Germany and the largest city of the German state of North Rhine-Westphalia with nearly 1.1 million inhabitants in the city proper and over 3.1 million people in the Cologne Bonn urban region. Cologne is also part of the Rhine-Ruhr metropolitan region, the…