Who is the antagonist in One Thousand Dollars by O.Henry?

The story "One Thousand Dollars" by O. Henry does not have a clear antagonist in the traditional sense. The main character, Mr. Kelcey, is not in conflict with any particular character or external obstacle but rather with his own internal desires and fears.

However, if we consider societal norms and expectations as an antagonist, it could be argued that the external pressure to conform to financial success and prestige poses a challenge to Mr. Kelcey as he contemplates whether to accept the thousand dollars or maintain his modest lifestyle.