In his book, he dealt with a significant bit of Charleston history in one inventive way.
"I talk about the sit-ins in 1958 along Capitol Street to integrate the diners. I was able to use some postcards -- typical store shots -- to tell that story," he said.
He does have one rare postcard dating from the early 1930s that depicts an African-American man in Charleston, kneeling beside a car and holding a dog.
"I was fascinated by that photo. First, because it was a picture postcard and there aren't a lot of postcards of African-Americans in Charleston. I was able to find our he had his own laundry service and it was over on Dryden Street. It got wiped out by urban renewal. It's underneath where the interstate is now."
Through that one postcard, he was able to tell several different stories, he said. "It was the only postcard from that traditionally black section of town. And I was able to show a black businessman and also able to show a street that no longer exists -- it was actually a thriving street in its day."
His Tuesday talk will focus mostly on Charleston's post-Civil War era from about 1880 to about 1920. That was "a golden age of postcards" and a special time in the city's development, Bumgardner said.
"That was a period of dramatic growth in Charleston history. It went from being kind of a small, sleepy town to really resembling closely what we still see, with a lot of landmarks we now identify with Charleston."
There are two types of postcards in his book and talk. The first is the most familiar kind -- published commercial postcards.
But there was another, rarer kind. Back in the day, camera shops that developed photographs had on hand a ready supply of postcard paper supplied by Kodak and other companies, said Bumgardner. "A lot of times if you wanted a picture developed, they'd develop it on photo postcard paper."
The result was a postcard that was sometimes one of its kind. His postcard history book features one such photo postcard of employees standing outside a clothing store on Capitol Street about 1905.
Photo postcards of big local events might be considered the Instagram snapshots of their day.
"When the Capitol burned in 1921, a lot of people took photos of it and you will see postcards of the Capitol burning. I've got several of the same shots," he said.
"In the case of disasters, they would actually sell them. The same thing happened with floods. They would make these photos quickly available."
Postcards can fill in the blanks in the landscape of what a city once looked like, said Bumgardner. "They can be a form of history, more in terms of architecture. Sometimes, the only photos we have of certain buildings are in postcard form."
Consider Luna Park, an amusement park on Charleston's West Side. The park operated from 1912 to 1923, until its roller coaster, the Royal Giant Dips, was destroyed by fire along with much of the park.
There are some actual photos of the park, "but they're relatively few," said Bumgardner. "I've seen, I think, three different postcard views of Luna Park. Without that, we wouldn't have a very good idea of what Luna Park looked like."
Reach Douglas Imbrogno at doug...@cnpapers.com or 304-348-3017.