According to the Guardian, King is the 15th wire fox terrier to win the top prize (the most of any breed).
There was a conflict of interest - top judge Peter Green's longtime partner has co-owned dogs with one of Colton's co-owners, including 2013 Westminster champion Banana Joe the affenpinscher.
"After you win this magnificent show there's really nothing else to win".
Baby Lars the Bouvier des Flandres won for the herding group.
Bono, a Havanese from Menlo Park, California named for the U2 frontman, was named reserve best in show after winning the toy group.
Bean the Sussex Spaniel won for the sporting group.
The dog show features 3,000 dogs from around the country. Colton the schipperke is out of the show!
"We never had any expectation of winning the Non-Sporting Group as no Schipperke in history has ever won the Group at this show and we focused exclusively on creating a spectacular performance in the breed- level competition", she wrote.
But Colton the schipperke was ruled ineligible for best in show after winning the non-sporting group on Monday.
But although King's performance was undeniably superb, viewers were outraged, instead calling for Best in Show to be awarded to the exquisite longhaired dachshund named Burns.
Burns the Dachsund won for the hound group.
The Westminster Kennel Club's show, in its 143rd year, is the second oldest US sporting event, behind only the Kentucky Derby horse race.
Colton, a six-year-old member of the Belgian breed, was "excused" because of ownership eligibility requirements set by the American Kennel Club, competition officials said. Brennan and Heart impressed the judge with a freestyle routine inspired by the 1956 film "The Red Balloon", which saw the dog tugging a red balloon at Brennan's command. Those two competitions are the only parts of Westminster that allow mixed-breed dogs (dubbed "all-American" dogs) to compete.
The show also featured an agility championship Saturday and is holding an obedience competition Monday.