If you want to get acquainted with Colonial Philadelphia, George W. Boudreau has arranged an introduction.

Boudreau, a transplanted Hoosier and cultural historian, opens the door to the city before 1800 with his book Independence: A Guide to Historic Philadelphia (Westholme, $24.95), copiously illustrated and fascinating for all the contemporary sources it cites as it strolls the narrow streets, eaves-dropping on long-ago Philadelphians.

One grows very fond of the Quaker diarist Elizabeth Drinker, both for the charm of her style and the vividness of her reportage. On Sept. 12, 1777, for example, she wrote that "the perticulars of the Battle [of the Brandywine], I have not attended to, the slain is said to be very numerous — hundreds of their muskets laying in the road, which those that made off have thrown down — I was a little fluttered this Afternoon by hearing a Drum stop at our house and a hard knocking succeed; it proved to be, men with orders for HD [her husband Henry] to appear or find a Substitute — there has been a meeting this Afternoon at the State-House, on what Account I know not."

From its very beginning, Philadelphia was a diverse and rapidly changing town.

"Philadelphia has more surviving early American buildings than any other city in the nation," Boudreau writes in Independence. But almost none of the buildings that date from the decades immediately following Pennsylvania's founding in 1681 — including William Penn's house — have survived. (Gloria Dei Church on Christian Street in South Philadelphia is likely the only surviving building in Pennsylvania that William Penn actually set foot in. The Letitia Street House, now in Fairmount Park, is one of the oldest buildings in the state, but was built after Penn left for England.)

What happened to those earliest buidlings?

"There was a style-shift in the early 18th century," Boudreau explained over lunch at the City Tavern, which itself dates to 1772. "The idea of beauty changed."

And the idea of preserving what had gone before had not yet taken hold. As Boudreau writes, "Independence Hall — or the old State House, as it was actually known — might easily have joined the list." But "the Marquis de Lafayette's visit to 'the hall of independence' in 1824 gave a new name and new meaning to the old office building."

The book, he says, "shows that from the beginning diversity was the rule here." He quotes Dr. Alexander Hamilton (no relation to that other Alexander Hamilton): "I dined at a tavern with a very mixed company of different nations and religions. There were Scots, English, Dutch, Germans, and Irish; there were Roman Catholics, Church [of England] men, Presbyterians, Quakers, Newlightmen, Methodists, Seventh day men, Moravians, Anabaptists, and one Jew."

For all his knowledge of and passion for Colonial Philadelphia, Boudreau who is an Associate Professor of History and Humanities at Penn State's Capital College in Harrisburg— is not a city native. He's a Hoosier. He grew up in Michigan City, Ind., and got his Ph.D. in history and American studies at Indiana University (the one in Indiana, not the one in Pennsylvania).

In graduate school, he says, "I became fascinated with the history of Pennsylvania because of its religious and cultural diversity, which didn't really exist in any of the other colonies." Later on, while doing research at the Historical Society of Pennsylvania and the Library Company, he had "this great revelation. I was trying to write about Franklin and his circle. I couldn't find anything, and I had to go home because I couldn't afford to stay any longer. Then, on my second to last day, the librarian said to me, 'I wonder if the minute books would be any good for you.' I told her probably not, but I wondered why they weren't in the card catalog, and she said, 'Because they're in the vault, George. We still use them. They're our business records.' Anyway, she brought them down on a cart and it was mind-boggling. It was like sitting at the table with Franklin and his friends. You could see the library being formed and the Enlightenment getting to the people."

In 1994, Boudreau received grant money to do research here, and has been here ever since. During two of those years, he was site director for the Powel House on Third Street and was intimately involved in its restoration. Actually, Powel House, though built in 1765, is a good example of what Philadelphia was like when Franklin arrived in 1723. The Delaware at that time came up to where I-95 is now. In other words, it fronted on Front Street, which is where Ben would have disembarked. He would have walked up High Street, which came to be called Market Street because of the two enclosed markets that took up the space between Front and Third. Beyond Third Street, it was mostly open country and farmland. And it is farmland that would have been outside the Powel House, its Georgian elegance notwithstanding.

It wasn't until the mid-18th century that Philadelphia took on the lineaments of a city. Called by one visitor "a miniature London," it was widely referred to as the Athens of America.

As Boudreau's book attests, it was a livelier place than one might imagine. Here, for instance, is a most unusual episode in the history of Christ Church at Second and Market, related in gossipy style:

One Sunday morning in July 1715, the congregants arrived for services to find the church locked up tight. The previous night, the sheriff of Philadelphia had arrested Christ Church's acting rector, the Rev. Mr. Francis Phillips, leading him bare-legged through the town in his nightshirt and putting him in the town's prison. Phillips was charged with slander; allegedly, he had said that he had slept with three women, including the wife of Anglican leader William Trent and the daughter of John Moore, one of the congregation's founders ….

The story didn't end there. Mob violence ensued, there was a trial, a challenge to a duel, and more.

There are, of course, more edifying tales, one in particular that nicely illustrates the diversity that has so intrigued Boudreau. It happened during the yellow fever epidemic of 1793, which cost some 5,000 people their lives — 10 percent of the city's population:

Absalom Jones and Richard Allen, two former slaves who were leaders of the free African American community stepped forward to organize blacks to nurse the sick of all races during the epidemic ….The first home they visited was on Emsley's Alley, where they found two young children … alone with their dead mother and dying father. By the end of the day, the two men had visited and cared for over twenty families. Soon, the [Free African Society] had established a corps of three hundred nurses to care for the sick.

Boudreau freely acknowledges that National Park Service does an outstanding job of telling the political story of Colonial Philadelphia. But there is a great deal more to the story — people not generally known and places not adjacent to Independence National Park and the Constitution Center.

So how would Boudreau advise the adventurous traveler to start widening his Colonial horizons? By looking beyond the events commemorated on Independence Mall "and seeing how early Americans lived their day-to-day lives."

Frank Wilson is a retired Inquirer book editor. Visit his blog Books, Inq. ? The Epilogue. Email him at PresterFrank@gmail.com.