What if you could watch a 1920s video of your grandmother or other relative and see the way she was, but at 25?

Susann Gilbert can, almost. One of her relatives lives on in silent films, and her voice is in some clips.

Tracing her family roots, Gilbert found some interesting sparks in hunks of tedious research. But a member of her family tree who especially caught her attention was a first cousin of her grandfather: actress Alice Calhoun. Naturally, Gilbert, a former performer, was interested in learning more about the silent star born in 1900. But she couldn't find much. "In Hollywood, people come and go. People get very forgotten," Gilbert said.

When the Mount Pleasant resident searched for information on the Web, she kept finding the same biography repeated on different sites and with mistakes, including eight different birth dates.

To set the story straight, Gilbert launched her own Web site to tell her relative's story.

The site is part of a larger movement to preserve America's 20th-century film and theater history here in the Lowcountry. Gilbert and three other Mount Pleasant residents maintain Web sites dedicated to the history of motion pictures and the state's single-screen theaters.

If our family trees tell us who we are, then maybe films tell us what America was. You can see how people dressed, how they lived and what they thought was funny, Gilbert said.

"If you want to understand the 20th century, study the movie theater," said John Coles, who maintains www.scmovietheatres.com with Mark Tiedje.

What the railroad was to the 19th century, the movie theater was to the 20th century. The railroad, the men said, united the country physically. The movie theater unified the country culturally and socially. A trip to the movie theater in the early days included news reels, cartoons and coming attractions in addition to the feature-length film.

After the movie, you grabbed a soda and talked about what you saw, Tiedje said.

The men have been studying the state's single-screen theaters because it limits the scope of their research to a specific period. The state's first theaters built for movies opened in 1915. In 1930, there were 200 single-screen theaters in South Carolina. Many towns, no matter how small, had one. Tiedje and Coles likened it to bringing the Internet to town. Cottageville, barely a bend in the road, with a gas station and maybe a nursery, opened a single-screen in 1941.

The men have been collecting people's theater memories via the Web site www.scmovietheatres.com. But they also traveled the state and others to gather information. During their travels, Tiedje and Coles often stuck out in the smallest towns. They were met with, "Who are you?" until the men said that they'd come to learn about the town's old theater.

"People open up, they share their personal stories once you ask them about their memories," Coles said.

The most common South Carolina story involves the excitement after hearing that a live Tarzan star would come to the theater. Everyone thought it would be Johnny Weissmuller. Instead, they were greeted by "Cheetah" the chimpanzee. Everyone thought it was the real Cheetah, Tiedje said, but it was a chimpanzee rented out by a Florence man.

By the 1980s, most single-screen theaters had disappeared. Twin and triple screens opened in the 1970s and 1980s, changing the way people saw films.

"Movie theaters in the 20th century are more representative of the American culture," Coles said. "I don't think the movie theaters represent anything today."

Tiedje said, "The movies still do."

Ken Robichaux, The Picture Show Man Web site director of operations, said films of the 20th and 21st centuries are a reflection of society's tastes because they are so commercial.

He limits the information on his Web site to the 20th century from the beginnings of film to the 1960s, about the time Hollywood's studio structure and its golden age had ended.

The history of motion pictures gives a general view of the 20th century. It includes entertainment, dance, technology, patent law, censorship, the rise of unions, social values — Robichaux's list goes on.

"It encompasses everything, and because of that, it's endlessly fascinating," Robichaux said.