At the heart of the three-day visit is the focus the young Duke and Duchess of Cambridge want to place on issues they hold dear, such as wildlife conservation and efforts to stop the illegal ivory trade.
"Royalty in the 21st century has found a niche by involving themselves in causes that will take generations to address," says Toronto-based royal historian and blogger Carolyn Harris.
"In William's case he's following in a very long family tradition," she adds, noting his father Prince Charles advocated organic farming before that was fashionable, while grandfather Prince Philip has been involved in the World Wildlife Fund.
During this visit, William will take a side trip to Washington, D.C., where, along with meeting U.S. President Barack Obama, he will attend a World Bank conference to talk about combating the illegal trade in wildlife parts.
While William is in Washington, Kate, who is expecting their second child in April, will visit a child development centre in New York.
When he returns to New York, William will go to a reception hosted by the Royal Foundation to recognize initiatives undertaken by wildlife conservation organizations.
Mad about the animals
"This is something that Prince William cares passionately about," says British author and royal biographer Penny Junor, noting his interest in wildlife conservation flows strongly from his interest in Africa.
"He fell in love with Africa years and years ago when he was a teenager, and he is mad about the animals there."
Of course in media-mad NYC, William and Kate will also take in a basketball game — and might brush shoulders with Brooklyn Nets fans Beyoncé and Jay Z — as the royals utilize their celebrity status to support a collaboration between the NBA, United for Wildlife and the Royal Foundation.
"In America, they are simply celebrities," says Junor, author of the biography Prince William Born to be King.
And reconciling that fact with their roles as members of the Royal Family leaves Junor with a sense of unease, especially when she considers some of the events on the royal itinerary.
One of those is an up-to-$10,000-a-plate dinner William and Kate will attend at the Metropolitan Museum of Art in honour of the University of St. Andrew's, the Scottish school where they met more than a decade ago.
"I've always been slightly anxious about the Royal Family sort of selling themselves, raising money on the back of dinners and things like that, access to them," says Junor.
"It's a question of 'Are they celebrities or are they members of the British Royal Family?' and I think … if they blur the distinctions, then it becomes a little bit difficult."
'Prepare to lose your heart'
Whatever interest William and Kate do attract will only be the latest chapter in the long tale of fascination Americans have for British royals.
"A royal visit to the United States always attracts a lot of attention," says Harris, noting the media frenzy extends as far back as a visit by Queen Victoria's eldest son, Albert Edward, in 1860.
There was even a "romantic narrative" in the newspapers of the day, says Harris, with headlines in the vein of "Prepare to lose your heart, the prince is coming."
More recently, the U.S.media frenzy surrounding William's parents, Charles and Diana, in 1985 featured her dancing with another celebrity — actor John Travolta — at the White House.
And years later, after the collapse of their marriage, the spotlight again swirled around Diana when she visited New York City on her own, staying at the Carlyle Hotel (where William and Kate are rumoured to be staying this time around).
"In the United States, Princess Diana struck a particular chord," says Harris.
"She was seen as glamorous but also vulnerable and able to relate to people. So the fact that William and Kate are perceived as following in Diana's footsteps, that's going to attract a tremendous amount of attention."
No royals of their own
Junor sees the U.S. fascination with Britain's royals lying in the fact that the U.S. doesn't have a Royal Family of its own.
"So many countries that have ditched their royals seem to have a fascination in the British Royal Family. I think it's true all over the world really."
But as fascinated as Americans may be with William and Kate, they won't be getting a glimpse of their son, 16-month-old Prince George.
The toddler is staying put with his nanny in the U.K.
"In Australia, where they took George …they were the visiting Royal Family," says Junor. But in America, she says, "having George on show would be slightly gratuitous."