Knauff (plaintiff) was born in Germany in 1915. She fled Germany to Czechoslovakia and England during World War II. She worked for the Royal Air Force in England and then the War Department of the United States when she returned to Germany. In 1948, she married a United States citizen and Army veteran in Germany with the permission of the commanding general. Knauff attempted to enter the United States in 1948 to be naturalized, but was excluded and detained. The Assistant Commissioner of Immigration and Naturalization recommended she be permanently excluded without a hearing, and the Attorney General adopted that recommendation. Knauff filed a writ of habeas corpus in the Southern District of New York based on the War Brides Act. The district court dismissed the writ, and the Court of Appeals affirmed the dismissal. The Supreme Court then granted certiorari on her appeal.