> The first neural network, the Mark 1 Perceptron, was invented during WWII for OCR.

You're about a decade off, the Mark 1 Perceptron was created in 1958 [0]. The original paper (A Logical Calculus of the Ideas Immanent in Nervous Activity) that introduced the idea however was written during WW2 (1943) [1].

[0] https://en.m.wikipedia.org/wiki/Mark_I_Perceptron

[1] https://en.m.wikipedia.org/wiki/A_Logical_Calculus_of_the_Id...