Applied Optimal Control (1969) was compiled from six years of Harvard, MIT, and AIAA courses — the adjoint method's curriculum vector, by Bryson's own account

Bryson's first-person 1980 retrospective documents the teaching-to-textbook pipeline directly: a 1963 two-week Harvard summer course ("attended by 100 engineers, most of whom were from industry"), a Harvard graduate course from 1963 also given at MIT in 1966, and a repeated 1967 AIAA continuing-education course afterward distributed "in the form of audio-cassettes and a slide-book" — then the book, extended from those class notes. Cited "over 520 times since 1969" as of 1980 [unverified-quant]. That the book's content carries the goods is confirmed from the Dreyfus 1990 primary (read directly): "Bryson and Ho explicitly gave in their 1969 book gradient formulas for exactly the multistage, free-terminal-state problem."

An unbundling worth keeping (the capture's real find): the harvested topic assumed the argmin blog makes this curriculum argument. It doesn't. Recht's "Mates of Costate" (2016) cites the book only as the accessible written record of the Lagrangian/adjoint derivation, standing in for Bryson's unobtainable 1961 symposium paper — a derivational-lineage claim, no pedagogy framing (and he dates the book 1968; standard record and Dreyfus say 1969 — discrepancy preserved, not corrected). The curriculum-vector story is real but it is Bryson's own, not argmin's. A topic question's pre-bundled attribution is itself a claim to check.

That this gradient paradigm traveled richly within control while remaining off AI's map is documented from the AI side: even as the field diagnosed its own failure as combinatorial explosion (claim-lighthill-1973-blamed-combinatorial-explosion), McCarthy's 1973 rebuttal to Lighthill dismissed control theory as having "little relevance to AI" (claim-mccarthy-1973-control-theory-little-relevance-to-ai).

So the optimal-control thread of moc-backpropagation-origins gains its transmission mechanism: Kelley/Bryson's gradient procedure (claim-kelley-bryson-optimal-control-precursor) reached a generation of engineers through courses and this textbook — while the neural-network community rediscovered the mathematics separately (claim-rhw-1986-reference-list-four-works). Hecht-Nielsen's 1990 Neurocomputing is the attested first to flag the book as a backprop presage in the NN literature (Tier 4 pointer, not load-bearing).