Final answer:
Bill and Sam's main objective in "The Ransom of Red Chief" is to kidnap a boy and collect a ransom, but the plan goes humorously wrong when the child causes chaos, leading them to pay his father to take him back.
Step-by-step explanation:
The main objective of Bill and Sam in "The Ransom of Red Chief" is to successfully kidnap a young boy named Johnny and receive a ransom for his return. However, their plan backfires as Johnny, who assumes the name Red Chief, proves to be more troublesome than he is worth. The boy's antics and mischief lead the kidnappers to a point of desperation where they ultimately agree to pay the boy's father to take him back, effectively reversing the ransom situation. The story, written by O. Henry, is often noted for its ironic twist and humorous depiction of a kidnapping gone awry.