Many legal scholars consider the colonial period irrelevant to the subsequent history of American law. In 1936 Roscoe Pound defined the ‘formative era’ in American law as the post-revolutionary era, and legal historians have been bound by that periodization ever since. More recently, Grant Gilmore, in his book The Ages of American Law, began his first age, the ‘age of discovery’, at approximately 1800; Gilmore claimed that American lawyers had the opportunity at that time to create an American law essentially from scratch. Morton J. Horwitz further strengthened the reigning assumptions regarding the unimportance of the legal history of colonial America in his influential book The Transformation of American Law 1780–1860. In Horwitz's view, what marks the American legal system is the instrumental use of law to promote social change, particularly to further commercial interests, and this aspect of the law did not exist until the early nineteenth century.