Glenn Lym is an architect and documentary filmmaker who has learned so much about his San Francisco roots, he can tell you just how far down into the ground those roots to.
"About 16 to 20 feet below where we are," Lym said standing in the middle of Minnesota Street in the city's Dogpatch neighborhood.
In the late 1800's, before landfill had raised the level of the ground to its current height, Lym's great-grandfather, Lim Lip Hong, built a ranch on this site to raise his family.
"He must have been incredibly smart. He was incredibly entrepreneurial," Lym said.
Lim's story is at the heart of Lym's documentary, tracing his family's story back to his great-grandfather's arrival in the United States. "He came to America when he was 12-years-old in 1855 and he was sent by his family to earn money and send it back," Lym said.
Just a few years later, records show Lim was one of the very first Chinese immigrants (of what would eventually be thousands) to work on the Transcontinental Railroad, completed 150 years ago this month. "He shows us in the record as one of the first 50," Lym said.
Lym believes his ancestor was changed by his experiences in the American west and may be why, Lim, when settling in San Francisco didn't move to Chinatown but rather to the ranch in Dogpatch. Lim wanted a place to keep the horses he had been accustomed to riding.
One historian, however, proposed a different theory to Lym.
"She said, 'You should know your great-grandfather and Chan Shee, your great-grandmother did this deliberately because it meant that they understood and wanted their children to live in a different kind of America,'" Lym said.
And that is what happened. Descendants of Lim Lip Hong now count themselves in the hundreds. From business people to artists to filmmakers, and endless variety of life paths. All starting from the same point.
"It's an American story," Lym said.