When Randall addresses his daughters as "Angelica, Eliza and Peggy", he is referring to the Schuyler sisters from the musical Hamilton.
The comic book that young Nicky is reading is Flash #143 (March, 1964).
Pitcher John Smiley played for the Pittsburgh Pirates from 1986 to 1991 and was traded to the Minnesota Twins in 1992. He led the National League with 20 wins in 1991, making the all-star team.
Justin Hartley who plays main character Kevin Pearson and K.T Thangavelu who plays the owner of the house that stands on the Pearsons former house were both in episodes of the reboot of Quantum Leap. Justin Hartley plays the boyfriend of a girl that the leaper Ben Song leaps into and K. T. Thangavelu plays the mother of another woman Ben leaps into.