Peter mentions that he can't get over Party of Five (1994) being cancelled. Both "Family Guy" and "Party of Five" were cancelled and brought back after letter writing campaigns by fans. In addition, Lacey Chabert who voiced Meg Griffin in season one and part of season two was a regular cast member on "Party of Five."
The title is based on the United States' motto found on the Great Seal, "E. pluribus unum", Latin for "Out of many, one."
When Lois is giving the tour of her house, her dress and hat match what Jacqueline Kennedy wore the day JFK was shot.
The Griffins live at 31 Spooner Street, Quahog, Rhode Island.
When Mayor Adam West is showing Peter that his home is not on the map and it zooms (briefly) into a close-up of the map, you can see the names of different streets, one of them is called "McFar Lane" in reference to Family Guy creator, Seth MacFarlane, though it's interesting to note that the street isn't the exact spelling of the creator's name.