Born in New York, David Plymire was brought to Huangyuan, northwest China’s Qinghai Province, before his first birthday. He spent 17 years growing up in this small town, where his father had devoted himself to treating the sick, teaching practical skills and helping local families.

After returning to the U.S. at 18, David never forgot the place he called home. In 1987, nearly 40 years after leaving, he made his first trip back. Over the next three decades, he made more than 20 trips between China and the United States, helping bring 31 pieces of medical equipment worth more than 6 million yuan (about 893,000 U.S. dollars) to Huangyuan.

"A person can have only one hometown in a lifetime, and mine is Huangyuan," he says.