America was created by 17th- and 18th-century settlers who were overwhelmingly white, British, and Protestant. Their values, institutions, and culture provided the foundation for and shaped the development of the United States in the following centuries. They initially defined America in terms of race, ethnicity, culture, and religion. Then, in the 18th century, they also had to define America ideologically to justify independence from their home country, which was also white, British, and Protestant. Thomas Jefferson set forth this “creed,” as Nobel Prize-winning economist Gunnar Myrdal called it, in the Declaration of Independence, and ever since, its principles have been reiterated by statesmen and espoused by the public as an essential component of U.S. identity.

By the latter years of the 19th century, however, the ethnic component had been broadened to include Germans, Irish, and Scandinavians, and the United States' religious identity was being redefined more broadly from Protestant to Christian. With World War II and the assimilation of large numbers of southern and eastern European immigrants and their offspring into U.S. society, ethnicity virtually disappeared as a defining component of national identity. So did race, following the achievements of the civil rights movement and the Immigration and Nationality Act of 1965. Americans now see and endorse their country as multiethnic and multiracial. As a result, American identity is now defined in terms of culture and creed.

Most Americans see the creed as the crucial element of their national identity. The creed, however, was the product of the distinct Anglo-Protestant culture of the founding settlers. Key elements of that culture include the English language; Christianity; religious commitment; English concepts of the rule of law, including the responsibility of rulers and the rights of individuals; and dissenting Protestant values of individualism, the work ethic, and the belief that humans have the ability and the duty to try to create a heaven on earth, a “city on a hill.” Historically, millions of immigrants were attracted to the United States because of this culture and the economic opportunities and political liberties it made possible.

Contributions from immigrant cultures modified and enriched the Anglo-Protestant culture of the founding settlers. The essentials of that founding culture remained the bedrock of U.S. identity, however, at least until the last decades of the 20th century. Would the United States be the country that it has been and that it largely remains today if it had been settled in the 17th and 18th centuries not by British Protestants but by French, Spanish, or Portuguese Catholics? The answer is clearly no. It would not be the United States; it would be Quebec, Mexico, or Brazil.

In the final decades of the 20th century, however, the United States' Anglo-Protestant culture and the creed that it produced came under assault by the popularity in intellectual and political circles of the doctrines of multiculturalism and diversity; the rise of group identities based on race, ethnicity, and gender over national identity; the impact of transnational cultural diasporas; the expanding number of immigrants with dual nationalities and dual loyalties; and the growing salience for U.S. intellectual, business, and political elites of cosmopolitan and transnational identities. The United States' national identity, like that of other nation-states, is challenged by the forces of globalization as well as the needs that globalization produces among people for smaller and more meaningful “blood and belief” identities.

In this new era, the single most immediate and most serious challenge to America's traditional identity comes from the immense and continuing immigration from Latin America, especially from Mexico, and the fertility rates of these immigrants compared to black and white American natives. Americans like to boast of their past success in assimilating millions of immigrants into their society, culture, and politics. But Americans have tended to generalize about immigrants without distinguishing among them and have focused on the economic costs and benefits of immigration, ignoring its social and cultural consequences. As a result, they have overlooked the unique characteristics and problems posed by contemporary Hispanic immigration. The extent and nature of this immigration differ fundamentally from those of previous immigration, and the assimilation successes of the past are unlikely to be duplicated with the contemporary flood of immigrants from Latin America. This reality poses a fundamental question: Will the United States remain a country with a single national language and a core Anglo-Protestant culture? By ignoring this question, Americans acquiesce to their eventual transformation into two peoples with two cultures (Anglo and Hispanic) and two languages (English and Spanish).

The impact of Mexican immigration on the United States becomes evident when one imagines what would happen if Mexican immigration abruptly stopped. The annual flow of legal immigrants would drop by about 175,000, closer to the level recommended by the 1990s Commission on Immigration Reform chaired by former U.S. Congresswoman Barbara Jordan. Illegal entries would diminish dramatically. The wages of low-income U.S. citizens would improve. Debates over the use of Spanish and whether English should be made the official language of state and national governments would subside. Bilingual education and the controversies it spawns would virtually disappear, as would controversies over welfare and other benefits for immigrants. The debate over whether immigrants pose an economic burden on state and federal governments would be decisively resolved in the negative. The average education and skills of the immigrants continuing to arrive would reach their highest levels in U.S. history. The inflow of immigrants would again become highly diverse, creating increased incentives for all immigrants to learn English and absorb U.S. culture. And most important of all, the possibility of a de facto split between a predominantly Spanish-speaking United States and an English-speaking United States would disappear, and with it, a major potential threat to the country's cultural and political integrity.