Philip K Dick’s The Man in the High Castle was the first of a genre, and still one of the most unassuming and best; the conditional history book, the speculative historical fiction. Dick’s question was “what if the Germans and Japanese had won the war?” and he played it out with the Japanese and Germans coming to the edge of war over the perceived evil of the Germans, much like happened really after the war. Meanwhile in a high castle a man writes a book about “what if the americans had won the war?”
Other questions that spring to mind: What if Napoleon had won? What if Edison had been honest? What if The Shining had been a rom-com? Oh, there’s an answer to that last one, and what a work of genius it is.