When Feynman met Dirac (2020)
This comment is not very popular, especially in America, but Feynman was by and large a showman. His most celebrated publication is path integral approach. Dirac had a paper earlier (known as Dirac’s little paper), so did Norbert Wiener in a different context, on this approach. They didn’t pursue path integrals, as they could not (and still people can’t) make sense of them rigorously. Feynman looked up that paper and expanded on it.He also drew useful diagrams, but you know ... :)