Answer by taking a quote from the following article:

Tracey Ullman was born Trace Ullman in Slough, Buckinghamshire, the younger of two daughters, to Dorin (nee Cleaver) and Antony John Ullman. Her mother was British, with Roma ancestry, and her father was a Roman Catholic Pole. On the subject of the spelling of her name: "My real name is Trace Ullman, but I added the 'y.' My mother said it was spelled the American way, but I don't think she can spell!

Ullman married producer Allan McKeown in 1983. They had two children: Mabel, born in 1986, and Johnny, born in 1991. Mabel worked as assistant to former Labour deputy leader Harriet Harman; she stood as a parliamentary candidate for the Labour Party in 2015, and subsequently went on to become a charity director. Johnny is an actor and currently writes for The Late Late Show with James Corden. On 24 December 2013, Allan McKeown died at home from prostate cancer, three days before their 30th wedding anniversary. Ullman's mother died in a fire at her flat on 23 March 2015. An inquest ruled the death to be accidental. She was 85 years old.  Ullman became an American citizen in December 2006 and holds dual citizenship in the United States and the United Kingdom. The results of the 2004 United States presidential election, and a comment made by actor Tom Hanks, prompted her desire to naturalise. "Tom Hanks was standing in a corridor at a party and I said something, and he was just very nice and he went, 'Oh, yeah. I know that but you're British. You know, you don't have to put up with that stuff ... I went, 'No. Actually I've been here a long time.' I thought, that's it. I'm going to join in. So I took the [citizenship] test." In 2006, she topped the list for the "Wealthiest British Comedians," with an estimated wealth of PS75 million. In 2015, Ullman's wealth was estimated to be PS77 million, making her the wealthiest British actress and female comedian. In 2017, The Sunday Times increased it to PS80 million.  She has described herself as a British republican. "Even as a kid, I never got why we pay people millions of pounds to be better than us." On a particular incident: "An MP once suggested I be put in the Tower of London for saying derogatory things about the royals."  An avid knitter, she co-wrote a knitting book, Knit 2 Together: Patterns and Stories for Serious Knitting Fun in 2006.

When did she come to the US?
Ullman became an American citizen in December 2006