More than 100 cheering students waving US and British flags have welcomed the Earl of Wessex at a boarding school for low-income children.
Edward is in Philadelphia for two days of events to mark the Queen's Diamond Jubilee.
Applause greeted his silver Range Rover led by a police motorcade through the ornate iron gates of the stately campus of Girard College, on the edge of a gritty neighbourhood north of central Philadelphia.
After speaking briefly with a group of children, he went inside the school's pillar-edged Founder's Hall for a private reception and lunch with officials and students involved in a youth development programme started by his father, the Duke of Edinburgh.
He was later joined by two students, the school's president and mayor Michael Nutter to plant an "Elizabeth" magnolia tree.
The Earl's great-great-grandfather, who would later be crowned King Edward VII, planted two trees at the school during what was the first royal visit to the US in 1860.
"This is a historic occasion for us," Mr Nutter said, "and certainly a wonderful treat for our young students."
Edward seemed to be taken by surprise when he was called to the microphone to speak, jokingly saying, "I love surprises", then briefly stating that he hoped it would not be another 152 years until a member of the Royal Family visited the school again.
Not a college as it name suggests, Girard College provides free tuition, housing and meals to first- through 12th-grade students, primarily from single-parent families. It was founded in 1848 with a bequest from wealthy Philadelphia financier Stephen Girard.
Edward's current tour of the United States also includes stops in New York, Chicago and Birmingham, Alabama.