After 12 years living in California, Chinese citizen Chae Chan Ping was ready for a visit home. He procured the necessary documents  for his departure and return journey, and set sail for China, where he spent the next year  reconnecting with friends and family. But when he returned to San Francisco  on October 8th, 1888, Ping and his fellow immigrant passengers were forbidden to disembark. Just days earlier, President Grover Cleveland had signed the Scott Act, which invalidated the legal documents allowing their re-entry to the United States. This policy threatened  to separate families and deprive Chinese immigrants  of their homes and livelihoods. Ping challenged the ruling, beginning a legal battle for the rights of thousands of Chinese immigrants. But his case inspired an even more controversial policy that continues to impact immigrants  around the globe. Discrimination against Chinese immigrants had begun decades earlier, when the California Gold Rush created a massive demand for labor. Initially, Chinese immigrants were welcomed as reliable workers and became essential parts of frontier communities. Many built railroads  and worked in the mines, while others operated laundries, restaurants, and general stores. The 1868 Burlingame Treaty even granted China favored trading status with the US, and allowed unrestricted migration between the two countries. But as large numbers of Chinese immigrants found success, American workers began  to see them as a threat. Politicians and labor leaders denounced them for driving down wages, and violence against Chinese individuals became increasingly common. This anti-Chinese sentiment soon found  its way into California’s courts. In 1854, following a murder trial where  a white man was convicted of murdering a Chinese man, the California Supreme Court  overturned the conviction, holding that Chinese eyewitness testimony was inadmissible. The court declared that Chinese citizens could not testify against  white defendants, citing similar precedents  forbidding testimony by Black and Native American individuals. This decision effectively  legalized violence against California’s Chinese population, inspiring mob attacks and campaigns for segregation. Before long, anti-Chinese sentiment reached the federal level. In 1882, Congress passed  the Chinese Exclusion Act, the first federal law that restricted immigration based explicitly on nationality. In practice, the Act banned entry  to all ethnically Chinese immigrants besides diplomats, and prohibited existing immigrants from obtaining citizenship. It also meant Chinese individuals couldn’t leave the United States and return without first applying for a certificate  of re-entry. This policy remained in place  until October 1st, 1888, when the Scott Act prohibited re-entry altogether, stranding Chae Chan Ping and thousands of other Chinese immigrants. In court, Ping argued he had followed  the proper protocol obtaining his re-entry certificate, and the government had not honored his legally issued document. This argument was strong enough to send his case all the way to the Supreme Court. But the justices ruled against Ping, invalidating thousands of legal re-entry certificates in one fell swoop. The decision led to Ping’s deportation and left up to 20,000 Chinese immigrants unable to return to the US. But arguably even more important  than the court’s racist ruling was the logic they used to support it. Traditionally, the Supreme Court is considered a check on the other two branches  of American government, offering judgment on policies passed by Congress and the president. In this case however, the court stated they had no power  to pass judgment on the Scott Act, since Congress had declared  the immigration policy “a matter of national security.” This decision set a unique precedent. Unless Ping's case was overturned, congressional and executive branches could claim national security concerns to pass whatever immigration laws they wanted. Throughout the 20th century, xenophobic government officials used  this power to freely discriminate against immigrant groups. The 1917 Asiatic Barred Zone Act  prohibited the entry of all South Asians. And a series of immigration acts  in the 1920s expanded restrictions throughout Asia,  Eastern Europe and southern Europe. Many of these restrictions were lifted after World War II, and the Chinese Exclusion Act itself was finally repealed in 1943— over 60 years after it was enacted. But the US government continues  to use this precedent to deploy sudden and sweeping  immigration policies, targeting journalists and dissidents  as well as ethnic groups. Little is known about what became of  Chae Chan Ping following his deportation. But the injustices visited upon him  and thousands of other Chinese Americans continue to impact immigrant rights  and liberties.