Over at his blog, Pastor Wes White has written a brief history of the Covenant of Works in Continental thought here. An excerpt:
The way that some people tell the story of law and Gospel and the covenant of works in the history of the Reformed Church, you might think that the Reformed Church was just a mass of confusion and debate on these points. According to their story, the only people who had a clearly defined doctrine of law and Gospel were the Lutherans. The story ends with modern theologians who are seeking to impose this Lutheran law/Gospel distinction into the Reformed Churches.
That story would better be classified as a form of ecclesiastical fiction. The true story is this. The Reformed Church has always believed that there were two distinct types of revelation in Scripture called law and Gospel, and the Reformed Churches have codified this view in their Confessions. They have always believed that it was a crucial heremeneutical [sic] tool for understanding the doctrines of Scripture, as I have demonstrated here. The innovators are those who want to deny the law/Gospel distinction and introduce confusion into what we have always clearly understood.
Eventually, Reformed theologians made use of the distinction between the covenant of works and the covenant of grace in order to clarify and explain the difference between law and Gospel. This is codified in our Confession, but it was accepted by nearly everyone in the Reformed Churches. Here's a brief account of how this took place.