The United States made an astonishing transition from scientific backwater to superpower over the course of just one century, culminating in the atomic bomb. This course will track the development of peculiarly American conceptions of scientific methodology in the context of this rapid transition. American conceptions of science tend to privilege the practical over the theoretical. We will focus on two such conceptions: operationalism and behaviorism. Operationalism was developed to reconcile a practical conception of physics with radical theoretical changes due to relativity and quantum mechanics. Behaviorism extended this account of the theory and practice to the domain of psychology. Special attention will be given to class discussion and reading primary texts: Major figures include Peirce, Bridgman, Boring, Stevens, and Skinner.