U.S. President Donald Trump’s challenge to the longstanding rule that anyone born in the United States, with only narrow exceptions, is automatically a citizen echoes ?a similar dispute that took place on the shores of San Francisco more than a century ago.

In the late 19th century, amid a wave of fervent anti-Chinese sentiment, the U.S. government sought to prevent a young man named Wong Kim Ark from re-entering the country upon returning by steamship from a trip to his parents’ homeland of China, contending that, despite being born in the United States, he was not a citizen. On March 28, 1898, the U.S. Supreme Court disagreed, recognizing that the U.S. Constitution’s 14th Amendment grants citizenship by birth on U.S. soil, including to those such as Wong whose parents were foreign nationals.

Now his great-grandson, a San Francisco area resident, worries that the principle enshrined by his ancestor’s case may be in peril.