6/27/2023
The following is a counterfactual concerning the survival of Lovecraft beyond 1937. It was posted as a comment on a dying link-aggregating website.
I would say by the time Annie passed away in 1941 that Howard would find himself at a crossroads and potentially buckle down and take on a real, paying job rather than revision. Perhaps by that time Howard might be hired by the Army to crank out stories to entertain the troops considering Howard already had a small but ardent following.
On the other hand, considering how Howard thrives in hot weather, he could move out west and live with Klarkash-Ton and potentially find work revising scripts for Hollywood (imagine his subsequent correspondence full of "these damnable jews didn't like my revision of abbott and costello meet frankenstein! at least their $500 means i can keep the creditors at bay for another month! and remarks about hollywood drivel despite it paying for his bread and butter).
Time marches on, he may soundly cheer the efforts of Roy Cohn and Senator McCarthy until he finds himself in their sights because The Shadow Out Of Time shows socialist/communist ideals in a good light. Either he rats others out, something quite ungentlemanly, or becomes a pariah and has to work under a pseudonym.
By the late sixties I would guess he'd find his footing again. Here's where I find myself going off into a fantasy. Howard meets a young African American woman, finds himself absolutely smitten by her erudation and how she is a superfan. Still Grandpaw is Grandpaw and his correspondence is rife with, "She's smart for her kind!" Then she gets him to drop acid and smoke weed. The moderation of HPL's character is thorough and complete, he writes The Acid Quest Of The Unknown Woodstock which is a mixture of his weird fiction, Thomas Pynchon's inscrutible prose, and accents from the Beat writers oeuvre.
Howard is honored with a Hugo as a grandmaster of his genre and another for TAQOTU for best novel, but turns it down much like Brando turned them down by having his now-wife Lucy attend and speak for him at WorldCon. HPL now has, as many crudely describe it, fuck-you money.
Howard returns to reclusion from the public eye, lives a happy life and enjoys a happy marriage. Visits SHG before Christmas of 1972 while she's in hospice, first time since their "divorce" (the divorce was never finalized). HPL's output becomes sparse but each story is celebrated regardless of its quality. He engages in a brief feud with Stephen King over King's style and eventually there's a détente rather than a peace accord.
By the late seventies people remark upon Lovecraft's continued vigor, which he ascribes to Lucy Washington-Lovecraft's devotion. He's merely living his best life during his twilight years.
The eighties happen, Lovecraft is largely overshadowed but involves himself in the creation of the Call of Cthulhu roleplaying game as a notable project.
With the approach of 1990, he finds himself positively enchanted with fishing except he always throws the fish back rather than cooking it. Some habits die hard.
When Lucy finds Howard's body on the morning of April 29th, 1991 there is a resurgence of interest in his work. Many of his older works are reprinted, his old correspondence rife with odious opinions come to light yet Lucy argues, "That is not the Howard I knew". Scholars make the pilgrimage to Provincetown to see the sights and visit Lucy for her perspective on Theobald, and one happens to discover inside one of Howard's drawers there are many vials of 'essential salts' in them but many more empty vials containing their residue.
In 2017 Lucy Lovecraft is buried next to her husband at Swan Point after pancreatic cancer takes her life. To the surprise of the coroner and doctors, it appeared that she had been suffering from pancreatic cancer for more than thirty years! The person who found the vials of essential salts returns to the Lovecraft home after her interment and finds all the vials empty.
After all that time, Lovecraft was engaged in his own pursuits to create those essential salts to ensure the livelihood of his beloved black bride. Since that supply had run out, Lucy would rejoin her beloved six feet under at the age of 68.