One of the names on the door bells at Marys apartment is T. Bickle, a reference to Taxi Driver (1976).
In addition to the Ayn Rand Day Care center returning from "A Streetcar Named Marge", a woman in the subway appears to resemble Rand.
The title refers to the 1961 song "Moon River" performed by Andy Williams , to whom this episode is dedicated.
This is the second time the Simpsons have visited New York City the first being The City of New York vs. Homer Simpson (1997) when they retrieve Homer's car illeaglly parked at the World Trade Center.