Gray was also the author of the 1898 case "United States v. Wong Kim Ark", ruling that "a child born in the United States, of parents of Chinese descent, who, at the time of his birth, are subjects of the Emperor of China, but have a permanent domicil and residence in the United States, and are there carrying on business, and are not employed in any diplomatic or official capacity under the Emperor of China, becomes at the time of his birth a citizen of the United States." 169 U.S. 649;705.