The ENIAC's 1949 Determination of π

In January 1950, George W. Reitwiesner published an article describing the first use of a computer, the ENIAC, to calculate the decimal expansion of π. Starting with Reitwiesner's description of the calculation, the ENIAC's architecture, how it was programmed, and the mathematics used, this article examines why the calculation was undertaken, how it was done, and what was subsequently learned.