In pictures: Prince William and Kate visit Boston

Britain's Prince William and Catherine, Princess of Wales watch the game between the Boston Celtics and Miami Heat at TD Garden in downtown Boston. REUTERS/Brian Snyder/Pool

Prince William, Prince of Wales and Catherine, Princess of Wales receive flowers from Henry Dynov-Teixeira, 8, as they depart Greentown Labs, which bills itself as the world's largest climate technology startup incubator, in Somerville,...more

Prince William, and Catherine, Princess of Wales watch the Boston Celtics and Miami Heat play at TD Garden in downtown Boston. REUTERS/Brian Snyder/Pool

Prince William and Catherine, Princess of Wales, interact with people during their visit to Roca, a non-profit organization focusing on high-risk young people between the ages of 16-24 years old, in Chelsea, Massachusetts. REUTERS/Faith Ninivaggi

The Princess of Wales during a visit to the Greentown Labs in Somerville, to learn about climate innovations which are being incubated in Boston. Kirsty O'Connor/Pool

Prince William points to a 1970's photograph of Queen Elizabeth and then Boston Mayor Kevin White while touring Boston City Hall with Catherine, Princess of Wales, and Boston Mayor Michelle Wu and her family.  Charles Krupa/Pool

People wait for Prince William and Catherine, Princess of Wales who are to meet with Mayor of Boston Michelle Wu and U.S. Ambassador to Australia Caroline Kennedy, in Boston. REUTERS/Brian Snyder

Prince William and Catherine, Princess of Wales, wave from a car as they visit Roca, a non-profit organisation focusing on high-risk young people between the ages of 16-24 years old, in Chelsea, Massachusetts. REUTERS/Faith Ninivaggi

People hold signs during Prince William and Catherine, Princess of Wales visit to Greentown Labs in Somerville, Massachusetts. REUTERS/Brian Snyder

William, Prince of Wales and Catherine, Princess of Wales arrive at Logan Airport. John Tlumacki/Pool

Catherine, Princess of Wales, interacts with people during a visit to Roca, a non-profit organization focusing on high-risk young people between the ages of 16-24 years old, in Chelsea, Massachusetts. REUTERS/Faith Ninivaggi

People wait for Prince William and Catherine, Princess of Wales who are to meet with Mayor of Boston Michelle Wu and U.S. Ambassador to Australia Caroline Kennedy, in Boston. REUTERS/Brian Snyder

Prince and Princess of Wales visit Boston City Hall.  Stuart Cahill/Pool

People hold signs during Prince William and Catherine, Princess of Wales visit to Greentown Labs in Somerville, Massachusetts. REUTERS/Brian Snyder

Prince William and Kate, Princess of Wales chat with participants of the Young Mother’s Program at Roca in Chelsea, Mass,. Reba Saldanha/Pool

People take pictures with their phones during Prince William and Catherine, Princess of Wales visit to Greentown Labs in Somerville, Massachusetts. REUTERS/Brian Snyder

Massachusetts Governor-elect Maura Healey looks on as Prince William is handed a basketball by Catherine, Princess of Wales as they watch the Boston Celtics play the Miami Heat at TD Garden in downtown Boston. REUTERS/Brian Snyder/Pool

Prince William and Catherine, Princess of Wales visit the Harbour Defenses of Boston. REUTERS/Brian Snyder/Pool

Onlookers take cellphone photos of the motorcade of Prince of Wales William and Princess of Wales Kate.   David L. Ryan/Pool

Catherine, Princess of Wales, smiles while Prince William looks on during their visit to Roca, a non-profit organization focusing on high-risk young people between the ages of 16-24 years old, in Chelsea, Massachusetts. REUTERS/Faith Ninivaggi

Prince William and Catherine, Princess of Wales speak with startup companies that work at Greentown Labs as they tour the location for a view of green technologies developed in Somerville, Massachusetts. Angela Weiss/Pool

Catherine, Princess of Wales, Emilia Fazzalari wife of Celtics owner Wyc Grousbeck, and Wyc Grousbeck watch the Boston Celtics play the Miami Heat at TD Garden in downtown Boston. REUTERS/Brian Snyder/Pool

Kate, Princess of Wales poses for a photo with the crowd after a tour of Roca in Chelsea, Mass. Reba Saldanha/Pool

Celtics owner Steve Pagliuca, former Celtics player and coach Tom "Satch" Sanders, Britain's Prince William, Catherine, Princess of Wales, and wife of Celtics owner Wyc Grousbeck, Emilia Fazzalari, watch the Boston Celtics play the Miami Heat at TD...more

The crowd awaits Prince William and Kate, Princess of Wales outside of Roca in Chelsea, Mass. Reba Saldanha/Pool

Prince William, Catherine, Princess of Wales and Massachusetts Governor-elect Maura Healey prepare to turn the lights on on Boston City Hall. REUTERS/Brian Snyder

Prince William and Catherine, Princess of Wales and Mayor of Boston Michelle Wu turn the lights on on Boston City Hall. REUTERS/Brian Snyder