Essentials of Economic Theory
John Bates Clark
John Bates Clark was an American adherent of the Marginalist School who engaged the Austrians and learned from them. He delivered many blows against the Historical School in favor of the idea of pure theory. He was also one of the first economists to emphasize the importance of potential completion in markets with a single or few firms and to view competition as a rivalrous process. Clark contributed to laying the foundation of what would later become a distinctly American Austrian School.
Mises regarded Clark as an outstanding economist, perhaps his favorite American economist.