It did and the man Adolf Hitler himself said that in his speech in the Sportpalast of Berlin on the 30th of September 1942).
Here is a link to the entire speech. Skip to the timestamp of 4:45 to know why Stalingrad was an important place. I do recommend listening to the entire speech to get the full context
And the follow up speech where he talks about logistics and the stops in german operations (although you can skip it, as he does not mention Stalingrad. Only how they fixed roads that the bolsheviks did not manage to and all the wonders the soviet people have accomplished under the Germans)
Here a speech from Stalingrad 1993… in which Hitler talks about why Hitler took Stalingrad, though it is heavily edited
which is taken from
(it is not subbed yet which is why I put in the quote from the subbed movies)
and if I remember correctly… In some regular episode Indy does mention that if the Germans were successful in taking Stalingrad… then the last rail link to the Caucus would be cut off.