On Sunday, Barron Trump and his mother, First Lady Melania Trump, officially moved into the White House — and all eyes were on Barron. The 11-year-old walked off Marine One with his parents and grandparents, playing with a fidget spinner, one of the most popular toys for young adolescents today, wearing New Balance sneakers and sporting a t-shirt that read "The Expert."

The funny t-shirt resonated with Americans, and within hours of the photo being spread throughout the mainstream media, it was sold-out online. The shirt is from J. Crew and costs about $30.

"We're sorry. This item has been so popular, it has sold out," reads the J. Crew site, where the shirt was sold pre-Barron photo.

Mrs. Trump was seen walking off the plane hand-in-hand with President Trump, wearing casual brown pants, holding a Birkin handbag and rocking Manolo Blanik shoes.

Melania and Barron were previously living in New York City while the 11-year-old finished up the school year. In the fall, Barron will attend St. Andrews Episcopal, located just outside of Washington.