(CNN) -- Prince William and Kate got the royal treatment Monday.
The Duke and Duchess of Cambridge chatted with President Obama and Hillary Clinton, received cheers from people on the street and met Jay-Z, Beyonce and King James -- also known as basketball star LeBron James.
They even got a look at American-style protest as demonstrators marched outside Barclays Center in Brooklyn to show their anger about the lack of an indictment in the Eric Garner chokehold death.
William and Kate arrived Sunday for a three-day trip, their first to the Big Apple.
Reporting from New York, CNN royal correspondent Max Foster said Kate was the star of the show. Screams greeted the Duchess of Cambridge when she arrived at a children's craft group in Harlem, greeted by the first lady of New York City, Chirlane McCray, amid tight security.
Excitement in the street
"They were very excited even to see the motorcade, and there is a real buzz around the city today," Foster said. "I think that association with Diana (Prince William's late mother), who used to come to New York a lot -- the biggest star in the world -- and Kate seems to be the closest replacement they have to Diana in this day and age."
Inside, Kate looked over some girls making crafts when an adult asked, "Do you know who's coming to visit you today?"
"Princess!" the girls said.
"And you know they think you're out of 'Frozen,' " the adult said. Kate laughed.
William jetted down to Washington for a quick visit with President Obama at the White House. The two men sat in chairs and tried to chat during a photo op while a swarm of reporters and photographers crowded around them.
The visit underscored "the special relationship" between the United States and the United Kingdom, the White House said.
William addresses World Bank
William next spoke at a session of the World Bank about the need for an international effort to stop illegal wildlife trading.
"Cooperation is our greatest weapon against the poachers and traffickers who rely on evading individual national initiatives," he said. "Our collective goal must be to reduce the wildlife trade by making it harder: denying traffickers access to transportation, putting up barriers to their illegal activities and holding people accountable for their actions."
William flew back to New York on a U.S. Airways shuttle, first class. One passenger tweeted a photo of the prince looking as if he were searching for a place to stash his carry-on luggage.
Another passenger, CNN's Anderson Cooper, tweeted, "Prince William just got on my DC shuttle flight" and "I'm hoping this means an on time departure." It did.
Monday night, William and Kate attended a reception organized by the Royal Foundation in recognition of the conservation work carried out by Tusk Trust and United for Wildlife partners, including the Wildlife Conservation Society, Conservation International and The Nature Conservancy.
Hillary Clinton, the former first lady and possible presidential candidate, was there, along with daughter Chelsea.
Basketball, Jay-Z and Beyonce
Finally, Kate and William made it to the Barclays Center for a game between the Brooklyn Nets and James' Cleveland Cavaliers. But before the game started, he met with NBA officials Adam Silver and Dikembe Mutombo for a photo op.
At the game in Brooklyn, the couple rubbed shoulders with Beyonce -- Queen Bey to her fans -- and her husband, Jay-Z. The celebrity couple used to be part owners of the Brooklyn basketball team.
The Cavaliers won the game, and afterward, James presented the couple with Cleveland Cavaliers basketball jerseys with the names "Cambridge" and "George" -- for their kid -- on the back.
Kate didn't say if this was the kind of thing she'd wear around the palace.
James also gave the couple cupcakes from his hometown and then appeared to joke with William about the size of their feet.
He asked William what his shoe size is and the prince quipped back: "Half the size of yours."
The princess, who is pregnant with the couple's second child, has battled acute morning sickness in recent months, and has had to cancel some events.
One person had to miss the trip. The couple's chubby-cheeked toddler, Prince George, stayed home in England.
CNN's Mariano Castillo contributed to this report.