I was fortunate to be the TA for a three-quarter undergraduate quantum mechanics class taught by Julian Schwinger at UCLA in 1979. Ch. 1 of my quantum text, Quantum Principles and Particles, posted here, is based on the first quarter’s notes, but with additions, deletions and diagrammatic interpretations. For those who would like to follow Schwinger’s original approach to quantum mechanics in this class, please see my original hand-written notes, posted below (146 PDF pages). Note these notes are simply copied out of my original UCLA notebook and look very rough, but one can still follow the clear arguments of the spin approach to quantum mechanics Schwinger pioneered. The notes also include the problems assigned.