In this paper, the first of a series, a historical overview of the conceptual development of the Old Atomic Theory is sketched, ranging from Bohr's first model for atomic structure, in 1913, to the proposal of the exclusion principle by Pauli, in 1925. Initially, arguments are given that aim to establish the validity and the relevance of a study of a research program such as the Old Atomic Theory, and an attempt is made to put that program in context within the framework of quantum theory in general. Next, one discusses topics such as: the structure of atomic spectra, the status of the correspondence principle, Sommerfeld's general quantum condition in terms of phase integrals, the elliptic-relativistic model of the atom, the Bohr-Kramers-Slater theory of radiation, Kramer's theory of dispersion, the concept of spin, the problem of the electronic configuration of atoms, and the structure of the periodic table, among others. An effort is made to present a history that highlights the inter-relations between concepts, and ample reference is made both to the primary sources and to the relevant secondary literature. The historical overview thus developed will serve as a basis for a second, forthcoming paper, in which Imre Lakatos' reading of the Old Atomic Theory will be critically analyzed. Although prepared originally with a view to serving as a reference for the ensuing paper, the present text can also be read in an autonomous way, functioning as a brief (and by no means exhaustive) historical introduction to this important and fascinating period of twentieth century physics.
Old atomic theory; Quantum theory; Correspondence principle; Quantization condition; Zeeman effect; Stark effect; Spectral series; BKS theory; Spin; Exclusion principle; Inconsistency; Bohr; Sommerfeld; Kramers; Slater; Pauli; Einstein
