As we strolled through St. Charles — a full moon illuminating the 250-year-old brick buildings, the gas lamps flickering on the cobblestone streets, a horse and carriage clopping along beside us — a shiver went up my spine.

It might have been the unsettling realization that we were visiting this Missouri town, called one of the most haunted places in America, on Friday the 13th. Whatever the reason, at that moment, the ghosts of St. Charles' past seemed to hover just out of sight, swirling in and out of the buildings on S. Main Street, whispering tales of the town's rich history.

One of those ghosts would surely be the city's favorite son, Daniel Boone. He came to this area with his family in the late 1700s after he had built a reputation as a legendary frontiersman, explorer and politician. If he were to return to St. Charles today, Boone might be confused by the enormous casino on the outskirts of town. He certainly wouldn't know what to do with the strip malls, highways and gas stations. But once he found his way to S. Main, he might very well exhale and say: "Ah, yes. I remember this place."

One of the oldest cities in the Midwest, St. Charles dates back to 1769. Historic S. Main Street meanders alongside the Missouri River for some 10 blocks, lined with meticulously restored limestone and brick shops and restaurants that look and operate much as they did centuries ago. They welcome visitors with locally made goods, a fine meal and warm hospitality.

It's what to do in St. Charles: Stroll along the river or the main street, weave in and out of the shops, enjoy a glass of wine, perhaps take a carriage ride. Oh, there are wonderful wineries and other historic sites nearby, and of course, there's that casino. But there's just something about historic downtown St. Charles that makes visitors want to steep themselves in the aura of this place.

Explorers' stamping grounds

My husband and I stayed in the Boone's Lick Trail Inn, one of two inns in renovated historic properties on S. Main. Its colonial furnishings and warm ambience hark back to the town's early days when trappers and traders would pass through needing a room for the night and a hot meal. Boone's Lick Trail was the only path through the uncharted West back in those days, linking up with the famous Santa Fe Trail.

Daniel Boone isn't the only giant of history to have a tie to this Missouri River town. Meriwether Lewis and William Clark rendezvoused in St. Charles on May 16, 1804, before embarking on their historic expedition, calling the town "the last civilized stop" on their grand adventure. The expedition stopped at Boone's home on their way westward.

Before Lewis and Clark left St. Charles, the townspeople — mostly French at that time — did it up right, throwing gala celebrations for the duo and their 40 men. Meticulous logs of the trip still exist, so we know that a crewman by the name of John Collins was found guilty of "misbehaving and using disrespectful language" at one of the balls.

Just off S. Main, a trail follows the Missouri River. It's parkland today, with gardens and bike trails and an old train track running through it. It's where Lewis and Clark camped and readied for their mission, so I wasn't surprised to find a bronze statue of the men there. But I was surprised by a third figure sculpted in bronze alongside these two national heroes. It was Seaman, Lewis' beloved Newfoundland dog, one of four dogs known to have accompanied the men on their journey.

Seaman's adventures were well documented — swimming in creeks, catching squirrels, retrieving fish, even howling at the incessant mosquitoes. He is the only animal to have survived the trip. Legend has it that he survived Lewis, as well, and was inconsolable upon the great man's death, howling mournfully on his master's grave until he himself passed away from grief.

Coincidentally, everywhere I looked, it seemed, somebody was walking a Newfie, perhaps in tribute to the heroic Seaman.

Now, about those ghosts …

With all that history, it's no wonder they say St. Charles is haunted. We took the ghost tour, which meanders up and down S. Main after dark. The bustling area quiets down, and that's when local historian and ghost aficionado Michael Henry transports visitors into the past.

Even if you're not into the ghostly aspect of the tour, it's a fantastic immersion into St. Charles' history. Henry's family has lived there for generations and he spent his life researching the history of the buildings, the inhabitants and which residents might still be floating around the streets today. If you want to know which house was a secret brothel during the Civil War or which prominent building has the bones of four men mysteriously buried within its foundation, he's the man to tell you.

"Every place in town claims to have a ghost," he sniffs, at the beginning of the tour. "Of course they all don't. I'm only going to tell you about the well-documented sightings."

There is the little lost girl who has been seen wandering the shops until she simply disappears. There is the elegant French couple, he with a waxed mustache, she in fine clothes, who have turned up in several of the restaurants and bars on Main Street. Servers approach the couple to offer them a table, only to watch as they fade from view. There's the big black dog that meanders through town, walking on a street that is 18 inches lower than where it sits today.

"Children see things other people don't see," Henry says, as he recounts how the children tell him that the dog's legs seem to vanish into the street below.

"The town drunks see it, too," he says with a wink. "They say: 'Oh, yeah. That dog without legs runs by here all the time. Barks, too.' "

It's thought to be one of the dogs from the Lewis and Clark expedition. Henry believes this, because several years ago, excavators found the bones of a large dog buried in a coffin in a part of that that had been a cemetery. Testing showed the bones to be from the Lewis and Clark era.

"It had to have been a dog of great stature to be buried in a human cemetery in a coffin," he says.

The Lady in White is the best known apparition in St. Charles, and she may also have ties to Henry's own family.

Henry has a letter written by an ancestor from St. Charles in 1822. It's not the cheeriest of correspondences. It was written during a cholera epidemic, by a man whose misery is heightened by the death of a young woman whom he obviously adored. He described her final days and funeral, and noted that she was buried wearing a white wedding dress with cream lace, in the cemetery that stood just off S. Main on 3rd Street, on the grounds of the old church where Lewis and Clark worshiped.

It's here that the Lady in White has been seen by countless people. She stands in front of the church quietly, like she is praying. She turns to look at those who see her, smiles sadly, then fades away.

We didn't encounter any of these ghosts on the tour that night. But as we walked back to our inn through the darkened streets — the shops and restaurants shuttered for the night, the gas lamps flickering — I could have sworn I heard the barking of a dog in the distance, as if the sound had floated there on a gust of wind from long ago.

Wendy Webb is the Minnesota Book Award-winning author of "The Tale of Halcyon Crane," "The Fate of Mercy Alban" and "The Vanishing."