German dead and wounded in France had been high. Field Marshal Walter Model said his 74 divisions had the strength of just 25. The Western Allies' supply problems gave the Germans time to rebuild their strength. In September, new troops were sent to the Siegfried Line. The total was 230,000 soldiers, including 100,000 new soldiers.
At the start of the month the Germans had had about 100 tanks in the West; by the end they had 500. As men and equipment were moved into the Siegfried Line they were able to establish a depth of .
The Allied force, under the command of General Dwight D. Eisenhower, wanted to capture the Ruhr. It was Germany's main industrial area.
General George S. Patton's Third Army was ordered to occupy the French region of Lorraine. General Courtney Hodges's First Army was ordered to attack near Aachen.
Hodges had at first hoped to go around the city. He thought it was only defended by a small group of troops which would surrender once they were cut off.
The beautiful, old city Aachen was not an important military target, as it did not do much war production. Its population of around 165,000 had not been bombed by the Allies.
It was an important symbol to the Nazi regime and the German people. It was the first German city threatened by an enemy during the Second World War. It was also the historic capital of Charlemagne, founder of the "First Reich". The city was very important to the Germans.
The city's defenders fought on home ground for the first time; one German officer said, "Suddenly we were no longer the Nazis, we were German soldiers."
Aachen was protected by the Siegfried Line, a system of pillboxes, forts, and bunkers protected by anti-tank obstacles and barbed wire. In several areas, German defenses were over deep. It was the strongest defence ever built.
Learning from their experiences on the Eastern Front, the Germans put their defences in the center of towns. They used narrow streets to make it hard for enemy armored vehicles to move around
Even though the troops defending Aachen and the Ruhr were of low quality, the fortifications protecting Aachen and the Ruhr were a major problem for the
American forces. Getting through Aachen was seen as important, because the land beyond Aachen was flat, and easy for the motorized Allied armies to travel on.
Fighting around Aachen began in the second week of September. The city was defended by the 116th Panzer Division, under the command of General Gerhard von Schwerin.
The closeness of Allied forces had caused the majority of the city's government officials to leave before the citizens were moved out. (For this, Hitler had all Nazi officials who had fled sent to the Eastern front as privates.) von Schwerin wanted to surrender the city to Allied forces. However, on 13 September, before he could surrender, he was ordered to launch a counterattack against American forces southwest of Aachen. He attacked with his panzergrenadier forces.
The German general's attempt to surrender the city made Adolf Hitler, ordered the general's arrest. He was replaced by General Gerhard Wilck. The United States' VII Corps continued to try to get past German defenses, despite the fighting on 12–13 September.
Between 14–16 September the US 1st Infantry Division advanced against strong defenses and attacks. Eventually, they had a circle around half the city.
This slow advance stopped in late September, due to the supply problem, and the sending of fuel and ammunition for Operation Market Garden in the Netherlands.
In October, Aachen's defense was assigned to General Friedrich Köchling's LXXXI Corps. These forces, along with the attached 506th Tank Battalion and 108th Tank Brigade, had 20,000 men and 11 tanks. Köchling was also promised a new 116th Panzer Division and the 3rd Panzergrenadier Division, with 24,000 troops.
The 183rd Volksgrenadier Division and 49th Infantry Division defended the northern approaches. The 12th Infantry Division was positioned to the south.
On 7 October, the 1st SS Panzer Division Leibstandarte SS Adolf Hitler Panzer Division were sent to defend Aachen.
Although new troops continued to arrive, the 12th Infantry Division had lost half its combat strength between 16–23 September, and the 49th and 275th Infantry Divisions had had to be given time to rest.
While German infantry divisions had a strength of 15,000–17,000 soldiers at the start of World War II, this had been reduced to a size of 12,500. By November 1944, the average strength of a division was 8,761 men.
To cope with the troop shortages, the Volksgrenadier divisions were created in 1944. Their average total strength was just over 10,000 men per division. Although about a quarter of these were experienced veterans, two-quarters were new soldiers and sick people while the rest were from the Luftwaffe and Kriegsmarine.
These divisions often received the newest small-arms, but they lacked artillery and motorization. The 183rd Volksgrenadier Division had not had time to train as a unit. The 246th Volksgrenadier Division was in a similar situation. Many of its troops had fewer than ten days of infantry training. All of these weaknesses of the troops were made up for by the strong fortifications surrounding Aachen.
The task of capturing Aachen was given to General Charles H. Corlett's XIX Corps' 30th Infantry Division and Joseph Collins' VII Corps' 1st Infantry Division.
General Leland Hobbs' 30th Infantry Division would be assisted by the 2nd Armored Division, which would try to go the 30th Division's hole in the Siegfried Line. Their sides were protected by the 29th Infantry Division.
In the south, 1st Infantry Division was supported by the 9th Infantry Division and the 3rd Armored Division. These divisions took in a large number of new men.
By 1 October over 70% of the men of General Clarence Huebner's 1st Infantry Division were new troops. The last two weeks of September were spent giving these men training in fighting and weapons training.
The plan called for both infantry divisions to avoid street fighting in Aachen. The plan was for the two divisions to encircle the city. Then a small force would capture it while most of the US forces moved east.
Although American units were usually able to get new troops quickly, the replacements rarely had enough training. Many junior officers were lacked tactical and leadership abilities. Some tank drivers had never even driven a car before. Some tank commanders had to teach their men how to load and fire their tank guns in the field before missions.
The US system meant that new troops reaching the front lines were not properly trained for combat. Sometimes half of a unit's replacements would become dead or wounded within the first few days of combat.
These losses required more troops to be brought into the fighting. A battalion of the US 28th Infantry Division was sent against Aachen to help the US 1st Infantry Division during 18–21 October.
These forces were supported by the Ninth Air Force, which knew where 75% of the pillboxes were. They planned an opening bombing using 360 bombers and 72 fighters. New aircraft would be used for a second attack, which included napalm.
With the Germans having few anti-aircraft guns and severely limited support from the Luftwaffe, Allied forces controlled the skies over Aachen.
For six days before the American attack allied artillery bombed German defenses around Aachen. Although bombing German LXXXI Corps to stop all movements of troops and supplies, it did not harm the pillboxes and strongpoints.
The opening air bombing on 2 October also did little damage to German defences. The 450 aircraft did not hit any German pillbox. Their targets had been hidden by thick smoke from the Allied artillery. After the aircraft finished their bombing, the artillery fired 18,696 shells.