In 1839, Ohio became the first state to adopt a bilingual education law, authorizing German-English instruction at parents' request. Louisiana enacted an identical provision for French and English in 1847, and the New Mexico Territory did so for Spanish and English in 1850. By the end of the 19th century, about a dozen states had passed similar laws. Elsewhere, many localities provided bilingual instruction without state sanction, in languages as diverse as Norwegian, Italian, Polish, Czech, and Cherokee.
Enrollment surveys at the turn of the 20th century reported that at least 600,000 primary school students (public and parochial) were receiving part or all of their instruction in the German language -- about 4% of all American children in the elementary grades. That's larger than the percentage of students enrolled in Spanish-English programs today. (Until recently, German was the dominant minority language.)
But political winds shifted during the World War I era. Fears about the loyalty of non-English speakers in general, and of German Americans in particular, prompted a majority of states to enact English-only instruction laws designed to "Americanize" these groups. Some went so far as to ban the study of foreign languages in the early grades -- a restriction that was struck down as unconstitutional in 1923.
Nonetheless, by the mid-1920s, bilingual schooling was largely dismantled throughout the country. English-only instruction continued as the norm for LEP students until its failure could no longer be ignored. LEP students in English-only classrooms were falling behind in their academic studies and dropping out of school at alarming rates.
The Bilingual Education Act of 1968 -- passed during an era of growing immigration and an energized civil rights movement -- provided federal funding to encourage local school districts to try approaches incorporating native-language instruction. Most states followed the lead of the federal government, enacting bilingual education laws of their own or at least decriminalizing the use of other languages in the classroom.