This paper offers a brief history of the development of curriculum knowledge as shown in 20th century publications. Observations about curriculum development are noted and recommendations are made for further exploration. Books and their authors are reviewed from the turn of the century to the present, beginning with theory predominance and the emerging schools of intellectual traditionalism, social behaviorism, and experientialism in the 1900s. Analytical interpretations dominated the twenties, school-oriented texts the thirties. In the forties, readings and synoptic texts appeared, and the sixties emphasized structure of disciplines and curriculum projects. Reconceptualists brought a revival of philosophic scrutiny and speculation in the seventies. The curriculum began as an inheritor of the three philosophies, grew as it created and outlined a future course of inquiry and developed into a purveyor of schooling. It then became preoccupied with the determination of substance and professed and generated knowledge about that. Now it is seeking freedom from the boundaries of that knowledge by returning to philosophy. Recommendations for the future include a need to search for the roots of curriculum study, and emulate these origins by perceiving curriculum as a function of culture. Curriculum inquiry should also be applied to outside curricula (other forces that influence the child's view of the world) and a knowledge of the student himself. (CK)