Daffy's friend, an invisible 6-foot kangaroo named Hymie, is an obvious reference to Harvey, a 1944 play about a man befriended by an invisible, anthropomorphic rabbit. The play was released as a movie 2 years later.
The three cities "conductor" Daffy names are a reference to the Jack Benny radio show. A running joke involved the Los Angeles Union Station conductor (played by Mel Blanc) announcing to Benny's entourage heading for New York: "Train leaving on Track five for Anaheim, Azusa and Cuc----amonga!"
The title comes from the advertisement for tourists: George Washington Slept Here.
In his appearance and vocal delivery the hotel desk clerk closely resembles character actor Franklin Pangborn, well known for performing such a role in numerous films.
Conventions still cause logistical headaches for hoteliers and attendees alike, even in 2023.