Order, lattices & Boolean algebra
Boole's algebra of logic: propositions manipulated as 0/1 algebraic quantities.
Founded: 1854 — Boole's An Investigation of the Laws of Thought
The claim
No credible dismissal found. Not dismissed, and not actually obscure. Boole's algebra spawned an active 19th-century logic tradition (Jevons, Peirce, Schröder), and Charles Sanders Peirce reportedly sketched an electrical-relay reading of logical operations decades before Shannon. What changed in 1937 wasn't the first hint that Boolean algebra could touch circuits — it was Shannon supplying the first systematic engineering theory showing it could design arbitrary switching circuits, turning a live logical tradition into a design method.
What happened
83 years — founding (1854) to Shannon's thesis (1937)
Verdict: Never dismissed, applied anyway.
Confidence: high.