A Personal Historical Introduction to Photosystem I: Ferredoxin + FNR, the Key to NADP+ Reduction -- The Discovery of Bound Iron–Sulfur 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 the Electron 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 Iron–Sulfur Clusters to Ferredoxin/Flavodoxin: Kinetic and Structural Properties of Ferredoxin/Flavodoxin Reduction by Photosystem I -- Electron Transfer From Ferredoxin and Flavodoxin to Ferredoxin:NADP+ Reductase -- The Interaction of Ferredoxin with Ferredoxin-Dependent Enzymes -- Electron Transfer Between Photosystem I and Plastocyanin or Cytochrome c6 -- Genetic Dissection of Photosystem I Assembly and Turnover in Eukaryotes -- Assembly of the Bound Iron–Sulfur Clusters in Photosystem I -- The Assembly of Photosystem I Reducing Site -- Thermodynamics of Photosystem I -- Application of Marcus Theory to Photosystem I Electron Transfer -- Modeling of Optical Spectra and Light Harvesting in Photosystem I -- Functional Modeling of Electron Transfer in Photosynthetic Reaction Centers -- Cyclic Electron Transfer Around Photosystem I -- Photoinhibition and Protection of Photosystem I -- Evolutionary Relationships Among Type I Photosynthetic Reaction Centers -- Convergent Evolution of Cytochrome c6 and Plastocyanin.