Can forced assimilation policies successfully integrate immigrant groups? As cross-border
migration surges, more countries must grapple with this question. A rich theoretical literature
argues that forced integration can either succeed or create a powerful backlash,
heightening the sense of cultural identity among the minority. This paper examines how a
specific integration policy — namely language restrictions in elementary school — affects
integration and identification with the host country later in life. I focus on the case of Germans
in the United States during and after World War I. In the period 1917–1923, several
US states barred foreign languages from their schools, often targeting German explicitly.
Yet rather than facilitating the assimilation of immigrant children, that policy instigated
a backlash. In particular, individuals who had two German parents and were affected by
these language laws were less likely to volunteer in WWII; they were also more likely to
marry within their ethnic group and to choose decidedly German names for their offspring.
These observed effects were greater in locations where the initial sense of German identity,
as proxied by Lutheran church influence, was stronger. These findings are compatible with
a model of cultural transmission of identity, in which parental investment overcompensates
for the direct effects of assimilation policies.