Under the direction of an American soldier, German civilians from Gardelegen carry wooden crosses to the site where they were ordered to bury the bodies of concentration camp prisoners killed by the SS in a barn just outside the town. It had been widely reported that members of the local population provided support to the SS during the operation
It has a Roman Catholic and three Evangelical churches, a hospital, founded in 1285, and a high-grade school. There are considerable manufactures, notably agricultural machinery and buttons, and its beer has a great repute. Gardelegen was founded in the 10th century (first named 1196), and was for a long time the seat of a line of counts. In 1358 Gardelegen became a city of the Hanse. It suffered considerably in the Thirty Years' War, and in 1775 was burned by the French. On the neighboring heath Margrave Louis I. of Brandenburg gained, in 1343, a victory over Otto the Mild of Brunswick.
On 13 April 1945, 1016 concentration camp prisoners were burned alive by the Germans in the Isenschnibbler Feldscheune. Today this area is the site of a memorial for the dead.
At the height of the cold war, a USAFRB-66 reconnaissance aircraft was shot down by Soviet fighters near the town on 10 March 1964. Her crew bailed out and was rescued and eventually handed back to West-Berlin by Soviet forces.
After having incorporated 18 neighboring towns and villages in 2011, Gardelegen is now Germany's third largest city by area, trailing only Berlin and Hamburg. It is actually the largest municipality in area in what was formerly East Germany.