Russell Thacher Trall (1812-1877) was an American physician who co-founded the first American Vegetarian Society in 1850. See his biography at IVU. In 1874, he published Hygeian Home Cook-Book, the first known vegan cookbook in America (also available for free online). According to Wikipedia,

What's remarkable is the similarity of Dr Trall's guidelines and Dr Esselstyn's (of WFPB-SOS) food guidelines from 2020. Dr Trall went a step ahead and removed even vinegar and condiments from his food system! Spice & condiment removal is a super-advanced food guideline that's adopted by the purest of Nature Cure advocates in India.

I learnt about Dr Trall from this article: "Leafy Greens — Six times a day — NO OIL" — the recommended diet for 2015 and 1874.