By the early 20th century, massive immigration from Europe caused schools to restructure and expand their programs to more effectively incorporate immigrant children into society. High schools began to include technical, business, and vocational curricula to accommodate the various goals of its more diverse population. The United States continues to be concerned about how to incorporate immigrant groups.
The language in which students are taught is one of the most significant issues for schools. Many Americans have become concerned about how best to educate students who are new to the English language and to American culture. As children of all ages and from dozens of language backgrounds seek an education, most schools have adopted some variety of bilingual instruction. Students are taught in their native language until their knowledge of English improves, which is often accomplished through an English as a Second Language (ESL) program. Some people have criticized these bilingual programs for not encouraging students to learn English more quickly, or at all. Some Americans fear that English will no longer provide a uniform basis for American identity; others worry that immigrant children will have a hard time finding employment if they do not become fluent in English. In response to these criticisms, voters in California, the state that has seen the largest influx of recent immigrants, passed a law in 1998 requiring that all children attending public schools be taught in English and prohibiting more than one year of bilingual instruction. .
Many Americans, including parents and business leaders, are also alarmed by what they see as inadequate levels of student achievement in subjects such as reading, mathematics, and science. On many standardized tests, American students lag behind their counterparts in Europe and Asia. In response, some Americans have urged the adoption of national standards by which individual schools can be evaluated.