Final answer:
The story 'Stage to Lordsburg' by Ernest Haycox was based on the short story 'Boule de Suif' by Guy de Maupassant.
Step-by-step explanation:
The story 'Stage to Lordsburg' by Ernest Haycox was based on the short story 'Boule de Suif' written by Guy de Maupassant.
In 'Boule de Suif', a group of travelers is traveling on a stagecoach during a war, facing various challenges and moral dilemmas along the way.
Haycox took inspiration from this story and adapted it to the American West setting in 'Stage to Lordsburg'.