A Personal Historical Introduction to Photosystem I: Ferredoxin + FNR, the Key to NADP+ Reduction.- The Discovery of Bound IronSulfur Clusters in Photosystem I by EPR Spectroscopy.- The Discovery of P430 and Work on Photosystem I Electron Acceptors FeS-X and A0 at the Charles F. Kettering Research Laboratory.- Historical Introduction to Photosystem I: The Discovery of the A1 and A2(Fx?) Acceptors by Time-Resolved Optical Spectroscopy.- Association of Photosystem I and Light-Harvesting Complex II during State Transitions.- Structural Analysis of Cyanobacterial Photosystem I.- Structure, Function, and Regulation of Plant Photosystem I.- Molecular Interactions of the Stromal Subunit PsaC with the PsaA/PsaB Heterodimer.- Accessory Chlorophyll Proteins in Cyanobacterial Photosystem I.- LHCI: The Antenna Complex of Photosystem I in Plants and Green Algae.- The Low Molecular Mass Subunits in Higher Plant Photosystem I.- Ultrafast Optical Spectroscopy of Photosystem I.- The Long Wavelength Chlorophylls of Photosystem I.- Mutagenesis of Ligands to the Cofactors in Photosystem I.- Genetic Manipulation of Quinone Biosynthesis in Cyanobacteria.- Optical Measurements of Secondary Electron Transfer in Photosystem I.- EPR Studies of the Primary Electron Donor P700 in Photosystem.- FTIR Studies of the Primary Electron Donor, P700.- Primary Charge Separation Between P700* and the Primary Electron Acceptor Complex A-A0: A Comparison with Bacterial Reaction Centers.- Fourier Transform Infrared Studies of the Secondary Electron Acceptor, A1.- Electrogenic Reactions Associated with Electron Transfer in Photosystem I.- High-Field EPR Studies of Electron Transfer Intermediates in Photosystem I.- Transient EPR Spectroscopy as Applied to Light-Induced Functional Intermediates Along theElectron Transfer Pathway in Photosystem I.- Electron Transfer Involving Phylloquinone in Photosystem I.- The Directionality of Electron Transport in Photosystem I.- Electron Transfer from the Bound IronSulflót