This is true.
When I was growing up, my mother would take me to this store in Williamsburg, before it became gentrified, to buy children’s clothing. We lived in another part of Brooklyn. so one day, my mother gets curious and asks the shop owner, whose, despite being a Chassid, how a Jew got the name Sean Fergusson. yes, his name was Sean Fergusson. He said, that when he was on line at Ellis Island, he got really nervous as he approached the uniform clerk, he lost his voice from being so nervous, so when the immigration official asked, “Jew! What is your name?” The Chassid said he answered in Yiddish, “shoyn Fergesen”. (I forget)
The non Jewish official hear, Shawn Fergusson and that is what he wrote down. So, to this day, that is his name.