A little bit of history
The capture of Stalingrad was important to Hitler for two primary reasons. Firstly, it was a major industrial city on the Volga River — a vital transport route between the Caspian Sea and Northern Russia. Secondly, its capture would secure the left flank of the German armies as they advanced into the oil-rich Caucasus region — with a goal of cutting off fuel to Stalin’s war machine.
In one day of heavy fighting during the battle of Stalingrad, a local railway station changed hands from Soviet to German control and back again fourteen times in six hours.