WARNING: The following contains spoilers for WandaVision Episode 6, "All-New Halloween Spooktacular!," now streaming on Disney+.
Episode 6 of WandaVision expands the border of the Westview Anomaly considerably, as Wanda pushes it out to save her husband. But prior to that point, its boundary was very clearly delineated, with Wanda telling her children not to go past "Ellis Avenue," the street that marks one edge of town. Vision visits that boundary in order to break through to the outside world, and Tommy and Billy seem to have been previously told not to cross it. With the name of the street featuring so prominently in the episode, it's easy to wonder where the inspiration for "Ellis" came from.
An easy first guess might be Warren Ellis, a long-time comics writer who's worked with Marvel on several long-running series, including Thunderbolts, Moon Knight and Iron Man. Such homages can be common in superhero television series, with The CW's The Flash making several references to comics writers via street names, including "Waid Boulevard" and "Infantino Street." What makes this less likely is Ellis' recent controversy over alleged sexual misconduct, which has seen the writer removed from work on Season 4 of Castlevania.
But there are multiple other namesakes for Ellis Avenue, and it's just as likely that the name is a reference to Ellis Island. Ellis Island is a small isle that sits in the mouth of New York Harbor and has been a long-standing immigration center for new immigrants coming to the United States. Ellis Avenue serves a similar role in Westview as a geographical boundary, and it's likely that Wanda would be aware of that, as she lived in the Avengers compound near New York for several months in between the events of Avengers: Age of Ultron and Captain America: Civil War. She admits in Episode 6 that she doesn't know how she created Westview, but it's clear from previous episodes that it's shaped by her subconscious and memory, modeled after popular American sitcoms.
It's also possible that Ellis Avenue doesn't even refer to a real-world person or place, and is instead a callback to the Marvel Cinematic Universe's Matthew Ellis. Iron Man 3 brought the United States government into an unexpected focus, as villain Aldrich Killian attempted to kill the president, Matthew Ellis. This is quite a departure from the real world, as the president when the film was set was Barack Obama. Fictional presidents are nothing new in media but are made even more confusing in the MCU due to multiple different writers' rooms.
Shane Black and Drew Pearce might have intended for Ellis to have replaced Barack Obama when they wrote Iron Man 3, but that message clearly wasn't passed on to the writers for Hulu's Runaways. Nico Minoru references "The Obama administration" in a throwaway line from the series' third episode, and executive producer Jeph Loeb has confirmed that the series is part of the greater MCU. If both Iron Man 3 and Runaways are contributing to the same timeline, then it's safe to assume that Ellis took over as president of the United States in 2012, after Obama had served at least one term in office.
Ellis reappeared briefly in Civil War, where he was responsible in part for the creation of the Sokovia Accords, the set of international laws that attempt to regulate superhuman affairs across the world of the MCU. Wanda's actions in Lagos were the direct cause for the creation of the Accords, so it's no surprise that she would name an insurmountable boundary after the president responsible for creating them. Either way, Marvel Studios very rarely points something out without reason, meaning there's clearly more to Ellis Avenue than meets the eye.
Written by Jac Schaeffer and directed by Matt Shakman, WandaVision stars Elizabeth Olsen as Wanda Maximoff/Scarlet Witch, Paul Bettany as Vision, Randall Park as Agent Jimmy Woo, Kat Dennings as Darcy Lewis, Teyonah Parris as Monica Rambeau and Kathryn Hahn as Agnes. New episodes air Fridays on Disney+.