Neilson Barnard/Pool/AP
The royals were greeted by crowds of fans and heavy security upon their arrival at the Carlyle Hotel, where they will stay for the duration of their trip.
Shortly after arriving, the couple was whisked away for a fundraising dinner at the Gramercy Park apartment of British advertising legend Sir Martin Sorrell of WPP.
There, the couple raised more than $2 million for their charity, the American Friends of the Royal Foundation of The Duke and Duchess of Cambridge and Prince Harry.
With only two full days in the US, the royals' schedules are jampacked. Here's what the couple has planned for Monday and Tuesday:
On Monday, William met with Obama in Washington, DC, while Kate visited a Harlem children's center with Chirlane McCray, wife of New York City Mayor Bill de Blasio.
The Duke of Cambridge met with President Obama ahead of William's speech to the World Bank on the illegal wildlife trade. He also joked about the "chaos" of his son George's birth.
Kevin Lamarque/Reuters
Shortly thereafter, the Prince spoke at the World Bank on behalf of United For Wildlife, a group of conservation organisations united to end illegal wildlife trade.
Jonathan Ernst/Reuters
Kate has repeatedly been compared to the late Princess Diana, who would also meet with children from disadvantaged backgrounds during her visits to New York.
Brendan McDermid/Reuters
Seth Wenig/Pool/AP
Mike Segar/Reuters
Jonathan Ernst/Reuters
On Tuesday morning, William and Kate will visit the 9/11 memorial and travel to the top of the Empire State Building.
Neither Kate nor Will have ever been to New York before, so they are eager to squeeze in some tourist activities while they're here.
Royal aides had originally not planned for Kate to go to the Empire State Building, thinking the pregnant princess would like some down time, but after seeing it was not on her schedule she reportedly told her staff she would like to go.
The Empire State Building commemorated the couple's first visit to the Big Apple by changing its lights to red, white, and blue - the colors of the Union Jack flag.
We welcome Their #Royal Highnesses The Duke & Duchess of Cambridge by sparkling in red, white & blue. #RoyalVisitUSA pic.twitter.com/o0tr84eKAI
- Empire State Bldg (@EmpireStateBldg) December 7, 2014
Later, the couple will attend a charity dinner at the Metropolitan Museum of Modern Art for St. Andrews University, where they met as undergrads in 2001.
The charity dinner celebrating St. Andrews' 600th anniversary will be held at the museum's Temple of Dendur exhibit, and will cost attendees a reported £85,000 ($132,991) per table.
Tom Hanks, Mary-Kate Olsen, and William's cousin, Princess Eugenie, are also scheduled to attend, the Daily Mail reported.