Reintegration for interwar migrants hinged on their nationality, which stateless people entirely lacked.

Evidence

The few chances for reintegration open to the new migrants were mostly based on their nationality: Spanish refugees, for instance, were welcomed to a certain extent in Mexico. The United States, in the early twenties, adopted a quota system according to which each nationality already represented in the country received, so to speak, the right to receive a number of former countrymen proportionate to its numerical part in the total population. — Hannah Arendt, The Origins of Totalitarianism, 2533

Categorization

• XREF: The US quota system as an early mechanism of nationality-based admission prefigures later immigration restriction by category — a useful factual anchor for the field’s arguments about bureaucratic sorting. — connects to: Postwar states granted privileged welfare only to ethnically defined ‘national migrants’ — Manuel Borutta and Jan C. Jansen, Vertriebene and Pieds-Noirs in Postwar…, 75