In 1924 HP Lovecraft married a jewish woman named Sonia Green.
The two of them went through a rough patch, she lost her business and became really sick, for awhile the two of them thought about separating, but the two of them stuck together through that hard time and she was able to convince him to take up the position of editor at weird stories.
While this position didn't pay much money, and Lovecraft hated Chicago the money gave him some stability and allowed him time to write some of his best works in relative comfort, as well as shape the world of horror, science fiction, and mystery in America.
Sonia is widely considered to be a good influence on her husband helping him overcome his racist tendenices, helping him in social situations, and keeping him on an even keel, but what if they had broken up what would the world of literature look like today?