This monumental collection of thirty-four historical papers on quantum electrodynamics features contributions from the twentieth century’s leading physicists: Dyson, Fermi, Feynman, Foley, Heisenberg, Klein, Oppenheimer, Pauli, Weisskopf, and others. The papers were edited by Julian Schwinger, who won a Nobel Prize for his pioneering work in this very topic. Physicists, mathematicians, electromagnetic engineers, and students of the history and philosophy of science will find much of permanent value in these essays. Reports range from initial successes to the first signs of crisis, followed by the stimulus of experimental discovery and new triumphs that led to an unparalleled quantitative accord between theory and experiment. The compilation concludes with the vision of quantum electrodynamics as part of the larger subject of the theory of elementary particles, faced with fundamental problems as well as the future prospect of even more revolutionary discoveries.