Frankfurt was absolutely destroyed in World War 2, there wasn't much the Americans had to do besides some sporadic combat in the ruined city.

Frankfurt had been bombed repeatedly in World War Two, 54 times prior to July 25, 1942. This was the important date since at this point, the British had not yet bombed civilian targets or population centers in the city. (The daylight raid on this day was the first direct civilian attack that took place on Frankfurt)

Two weeks later Frankfurt was bombarded again by 226 bombers. In January of 1943, the British and Americans decided to unite their Bombers, and on April 11, the savage attacks began again. This was followed by another large scale attack on October 4, 1943 when 650 aerial mines, 217,000 incendiary bombs and 16,000 liquid incendiary bombs were dropped by 300 British airplanes.

Frankfurt was further attacked on November 26 (1943), December 20 (1943), and January 28 (1944). On January 29, 1944, more than 800 American bombers dropped 5,000 high-explosive bombs and 10,000 incendiaries over the entire city. The culmination of these attacks killed people in the high hundreds. On February 8, 1944, 88 American bombers struck mostly industrial areas and killed only a few hundred.

On March 18 (1944) Frankfurt was bombed again and once again in an especially brutal bombing run on March 22 (1944) by 800 British bombers that destroyed the old city forever with more than 9,000 separate fires spread around the entire city. These fires were caused by this brutal British bombing campaign that dropped 1,300 high explosive bombs up to 8,000 pounds, 600,000 incendiary bombs and 50,000 liquid incendiary bombs that rained death and destruction upon Frankfurt from the medieval city center out. By now, thousands of civilians were dead and 150,000 shelterless.

Then 175 American bombers dropped bombs on the city center to polish it off shortly afterwards.The only civilians even left were the maimed, injured, orphaned, deranged, or elderly people and rescue workers.

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