The deportation order had been issued by Attorney General Tom C. Clark, using wartime powers granted by President Harry Truman in the waning months of World War II.

The detainees argued that the US Court for DC had jurisdiction because they were being held "subject to the custody and control" of the Attorney General.

Since Attorney General Clark fell within the jurisdiction of the D.C.-based District Court – and was arguably the custodian of the Ellis Island detainees – Ahrens argued that habeas could issue notwithstanding their remote location.

Concerns such as flight risks, travel costs, and administrative issues, Douglas continued, further counsel restraint against reinterpreting § 452 in the manner advanced by Ahrens.

After it has been properly invoked, jurisdiction cannot be defeated by subsequent conduct removing the parties from the court's territorial reach.

Over fifty years later, however, the Court explained in Rumsfeld v. Padilla, 542 U.S. 426 (2004) that in habeas cases challenging present physical confinement, the 'immediate custodian' is the proper respondent.

For if absence of the body from the jurisdiction is alone conclusive against existence of power to issue the writ, what of the case where the place of imprisonment, whether by private or public action, is unknown?

And if the place of detention lies wholly outside the territorial limits of any federal jurisdiction, although the person or persons exercising restraint are clearly within reach of such authority, is there to be no remedy, even though it is American citizens who are wrongfully deprived of their liberty and Americans answerable to no other power who deprive them of it, whether purporting to act officially or otherwise?

The United States detained hundreds of foreign captives at a US Navy facility in Guantanamo Bay, which it held was outside the territorial jurisdiction of all federal district courts.