"The Day After the Day the Martians Came" is a 1967 short story by American writer Frederik Pohl, first published in Harlan Ellison's anthology Dangerous Visions.
The narrative takes place entirely within the lobby of a Florida hotel, one day after a NASA ship carrying several live Martians returns to Earth. Their assignments completed, a large group of journalists are loitering in the hotel's bar waiting to check out. Jaded and blasé, the reporters pass the time by playing poker and telling Martian jokes (which are simply mundane ethnic jokes with Martians swapped in for normally-targeted human subgroups such as Poles.) Mr. Mandala, the hotel's small-minded manager, views the discovery of the Martians with indifference (except for the windfall profits the hotel has made.) After the last of the reporters has left, he remarks to one of his black bellhops - whom he habitually treats with petty condescension - that the Martians mean nothing, to which the bellhops gnomically replies that they mean a great deal to him.
The story was adapted (under the same title) by Marvel Comics in Worlds Unknown #1, May, 1973, illustrated by Ralph Reese.
A follow-up, "Sad Solarian Screenwriter Sam," was published in the June 1972 issue of the Magazine of Fantasy and Science Fiction. It followed a day in the life of an ambitious Hollywood screenwriter, who is suddenly inspired to attempt to capitalize on the media hype surrounding the arrival of the Martians by pitching a film adaptation of Edgar Rice Burroughs' Barsoom novels. The pitch fails due to screenwriter not having taken a sufficient interest in the nature of the actual Martians, who are not very telegenic.)
After a nearly fifteen-year interval, Pohl revisited the setting in the mid-80s. Five new short stories set in the same milieu were published in Asimov's, MF&SF, and Omni between 1986 and 1987:
In 1988, the seven existing stories were combined with three previously-unpublished ones (The Missioner, The Beltway Bandit, and Across the River) and nine short non-narrative interstitial vignettes (written in a quasi-journalistic style) to form a fix-up novel, The Day the Martians Came.