Yuma Simpson (nee Hickman), was the mother of Abe and Homer's paternal grandmother, who was apparently from "The Old Country", which was most likely the United Kingdom, Ireland, or Canada. Her name was revealed on The Simpsons Uncensored Family Album but it was never mentioned on the series.
Yuma Hickman was born in the Old Country (assuming Abe's story is to be trusted), to Willard Hickman and Theodora Hickman. Yuma married Orville Simpson in the early 1920s. They had at least twelve children, including Hubert, Tyrone, Cyrus, Abraham, Bill, Fester, Chet and Hortense. The family emigrated to the USA when Abraham was a young child, and for a few years, they lived inside the Statue of Liberty, along with their sons, until the head of it was filled with too much garbage. While in the US, they would initially settle in Albany. Later, the family would move to Springfield, USA, the town in which the show is set. Although Yuma's death has never been mentioned, she presumably died before her great-grandchildren Bart, Lisa or Maggie were born.
- Episode – "Much Apu About Nothing" (flashback)
- Episode – "Bobby, It's Cold Outside" (Mentioned in Flashback)
- Book – The Simpsons Uncensored Family Album
- Comic book – Abe's First Radio