HOW DOES A red-blooded American greet a prince anyway?

While hundreds of Philadelphians turned out over the weekend to take a gander at Prince Charles and wife Camilla, Duchess of Cornwall, on their first official visit to town, many questioned how they were supposed to react to royals in the very town that kicked the monarchy out.

Philadelphia is, after all, the birthplace of liberty.

"My ancestor fought with Washington in the revolutionary war," said Sarah Mitchell, 56, who came by the International House in West Philadelphia Saturday afternoon before the royals were supposed to make a visit. "So we fought against the British. I'm probably not going to stay."

Earlier in the day outside Independence Hall, where the duo made their first, stop, Kristen Donato, of Gloucester County, N.J., wondered how she should talk to Charles if he greeted the crowd of hundreds.

"What's the official wordage? 'Pleased to meet you, sorry my hand's cold'?" asked Donato.

In all, the roughly 24-hour royal visit to Philadelphia seemed to go off without a hitch. Charles and Camilla took in a number of historical sites, visited a mural being painted in West Philly, met students at the International House and attended the posh Academy Ball with a concert featuring Rod Stewart.

Yesterday, after a service at Arch Street Presbyterian Church, they boarded a private train to New York where Charles received an environmental award last night, presented by Al Gore.

Also on the train were five Philadelphians who work on urban and youth development, both interests of the Prince. Among them was Sister Mary Scullion of Project HOME, who said Charles impressed her during the 45-minute group discussion.

"I think that what impressed me was the breadth of his knowledge and depth of his knowledge," she said. "I was never aware before this visit how interested he was in low-income people and the environment."

The prince has been under attack by environmentalists in Britain for flying over here to receive the award - and reserving the entire first-class section of a plane for his entourage - given that he has pledged to reduce the amount of carbon dioxide caused by his travels.

British environmental activist Joss Garman told London newspaper The Independent: "If the prince was serious about dealing with carbon emissions, he wouldn't be flying all that way to receive an award for environmentalism in the first place. It is a form of eco-insanity to expend so much energy for such meagre reasons."

No environmental activists were seen at Independence Hall or the International House yesterday, although anti-fur group PETA made more than one appearance.

In general, reactions to the royal couple were mixed. Early Saturday several hundred gathered outside Independence Hall.

"She's personable," said Debbie Leferve, 49, of Philadelphia, who gave Camilla a bouquet. "She said she was happy the purple flowers matched."

But some people were tourists who couldn't get into the historical landmarks because of the royal visit.

"We came to see the Liberty Bell and Independence Hall and kind of got stuck," said Donna Mitchell, 33, of Florence, Ala., who was in Philly for the weekend with her husband. "We might as well [stay]. We've got a cousin that grew up in Britain, so we'll send the pictures to her."

Inside at the Liberty Bell, fifth-graders from the Loesche School, in Northeast Philadelphia, worked on projects for Charles and Camilla to observe.

Their teacher, Susan Anmuth, said the class had been learning about the monarchy.

"We've been working for two weeks," she said.

"They still have trouble understanding he's prince just because his mother's the queen."

She added that while they had been prepped on how to address Charles - as "Your Royal Highness" - there were to be "no curtsies and no royal waves."

Over at the Constitution Center, Philly's elite gathered, garbed in fur wraps and big hats, for a lunchtime reception.

Gov. Rendell, Mayor Street and Sen. Arlen Specter spoke before Charles took the stage.

Rendell complimented Charles for his fundraising, noting that the Prince oversees 17 foundations that raise 200 million pounds a year. Charles teasingly corrected him, saying he raises that much in dollars, not pounds.

"I'm not sure what the exchange rate was this morning," he said.

Charles spoke about how his great-great grandfather, King Edward VII, visited Philadelphia in 1860. At that time Edward was also Prince of Wales.

He drew a big laugh with this joke about the prominent Biddle family of Philadelphia.

"It seems that King Edward also caused something of a stir when, for reasons known only to himself, he seemed to think he had met a charming family named Scrapple and discovered a food named Biddle," Charles said.

The royal couple's Saturday fashion choices were conservative, but elegant. Camilla spent the day in a brown tweed fur-trimmed coat over a periwinkle cashmere dress, and changed into a long brown velvet dress at night.

Charles wore a navy double breasted coat and blue double-breasted suit with a red, blue and gold tie for day, and wore a white tie and tails with an assortment of military medals at night.

"I would imagine it had to be a difficult day for him," said radio personality Jerry Blavat, who met Charles at the Academy.

"He looked very refreshed, very relaxed." *