TLDR but i searched the linked page for america and the only mention is a theory, no proof: "In 1930 Austrian-American economist Gottfried Haberler detached th

TLDR but i searched the linked page for america and the only mention is a theory, no proof: "In 1930 Austrian-American economist Gottfried Haberler detached the doctrine of comparative advantage from Ricardo's labor theory of value and provided a modern opportunity cost formulation. Haberler's reformulation of comparative advantage revolutionized the theory of international trade and laid the conceptual groundwork of modern trade theories."