Let’s look at another Queen’s Gambit Declined, played between Harry Nelson Pillsbury and Jackson Whipps Showalter in their match of 1897. It provides an excellent example of how Black can obtain a dangerous queenside pawn majority with …c5-c4.
The match itself ended in a rather convincing victory for Pillsbury and had a not inconsiderable prize (for those days) of $2,000. Also interesting was the fact that Pillsbury played the Berlin Defence in a number of games but Showalter answered 1. e4 e5 2. Nf3 Nc6 3. Bb5 Nf6 4. O-O Nxe4 5. d4 Nd6 with 6.Ba4 rather than 6.Bxc6. These old guys knew something about chess!