IV. Federal Law Defines the Nation

Who Could Belong to America?

After Reconstruction ended, the states rebuilt racial hierarchy within their borders. At the same time, the federal government was constructing another part of the same system. Through immigration laws, citizenship laws, territorial expansion, and court decisions, the federal government decided who could belong to America and who could not.

Just as state law determined who could vote, where people could live, and which schools they could attend, federal law determined who could become part of the American people in the first place. That question was not abstract. It shaped who could enter the country, who could become a citizen, who could own land, who could vote, and who could claim the Constitution's protection. Federal law did not merely reflect racial hierarchy. It helped build and preserve it.

From the late nineteenth century into the mid-twentieth century, Congress, the federal courts, and federal agencies used immigration, naturalization, territorial law, and citizenship rules to draw racial lines around the nation. The law did not treat all nonwhite peoples the same. Black Americans remained at the center of the racial order created by slavery and defended by Jim Crow. But Asian immigrants, Mexican workers, Puerto Ricans, Filipinos, Native nations, and Native Hawaiians were also placed into legal categories that marked them as outside full belonging.

The central question was simple: Who was the nation for?

Citizenship and the Color Line

For much of American history, naturalization law answered that question openly. Citizenship by naturalization was reserved for “free white persons.” After the Civil War, Congress extended naturalization to persons of African descent. That change mattered. But it also exposed the structure of the law. Many Asian immigrants, and others deemed neither white nor Black, remained outside the nation's naturalization laws.

Excluding Those Deemed Unfit

Congress made that exclusion unmistakable in its treatment of Chinese immigrants. Chinese workers helped build railroads, worked in mines, labored in agriculture, and built communities across the West. When white workers and politicians portrayed them as both an economic and racial threat, Congress responded with the Chinese Exclusion Act. The law did not simply limit immigration. It declared that Chinese immigrants were racially unfit for membership in the nation.

This was federal racial policy. The United States could welcome labor while refusing to accept the laborers as future citizens. It could benefit from their work while denying them full membership in American society.

Congress followed the same pattern as it adopted broader immigration restrictions. Federal law increasingly excluded Asian immigrants and favored immigrants from northern and western Europe. Immigration law became another tool for maintaining racial hierarchy by protecting whiteness as the nation's preferred identity.

When Courts Decided Who Was White

The federal courts then had to decide who counted as white. These cases reveal the absurdity and danger of racial law. People went to court claiming whiteness because whiteness carried legal power. It opened the door to naturalization, land ownership, and the full rights of citizenship.

In Ozawa v. United States (1922), the Supreme Court rejected the naturalization petition of a Japanese immigrant who argued that his skin was as white as anyone else's and that he had embraced American language, culture, and values. The Court held that “white person” meant someone who belonged to the Caucasian race.

Only a year later, in United States v. Bhagat Singh Thind (1923), the Court faced the opposite problem. Bhagat Singh Thind, an immigrant from India, argued that anthropologists classified people from northern India as Caucasian. This time, the Court abandoned the scientific definition it had relied on in Ozawa. Instead, it ruled that “white” meant what the ordinary American understood the word to mean—and that Thind did not qualify.

Within a single year, the Supreme Court used two different definitions of whiteness. When science did not preserve the racial hierarchy, the Court abandoned science. When ordinary understanding better protected the racial hierarchy, the Court abandoned science and embraced common understanding instead. The objective was never consistency. The objective was preserving whiteness as a privileged legal status.

These decisions expose an important truth about American law. Race was not simply recognized by the courts. It was constructed by the courts whenever necessary to preserve racial hierarchy. The law did not merely reflect ideas about race. It actively shaped them, deciding who could become an American and who would remain outside the boundaries of full national belonging.

Empire Without Equal Citizenship

Federal law also defined belonging through territorial expansion. After the Spanish-American War, the United States acquired Puerto Rico, Guam, and the Philippines and annexed Hawaii. This expansion raised a fundamental constitutional question: Did the Constitution fully follow the flag?

The answer was often no.

Through the Insular Cases, the Supreme Court allowed the United States to govern territories without extending the full protections of the Constitution to the people who lived there. The nation could possess territories without fully incorporating their people. It could rule without equal membership. That was empire justified through constitutional doctrine.

The annexation of Hawaii reflected the same exercise of federal power. After overthrowing the Hawaiian Kingdom, the United States redrew the nation's boundaries and determined the political status of Native Hawaiians. Federal law decided not only where America ended, but who would be governed under its authority.

Puerto Ricans eventually received statutory U.S. citizenship, but that citizenship did not bring equal political power. Residents of Puerto Rico still lacked voting representation in Congress and could not vote for president while living on the island. Filipinos were treated differently again. They were U.S. nationals for a time, but not full citizens, and their legal status shifted with colonial policy and eventual independence.

Territorial expansion belongs in the story of racial hierarchy because the federal government was deciding far more than where the nation's borders would be. It was deciding the legal status and constitutional rights of millions of people brought under American control.

Native Nations and Conditional Citizenship

Native peoples faced another form of legal exclusion. Native nations existed long before the United States. Yet federal law treated Native people as members of separate political communities whose lands could be taken, whose governments could be limited, and whose citizenship could be delayed or conditioned.

The Indian Citizenship Act of 1924 extended U.S. citizenship to Native Americans born in the United States. That was an important legal milestone, but it did not end the problem. Citizenship did not restore stolen land. It did not undo allotment. It did not fully protect tribal sovereignty. And many states continued to deny Native people the practical ability to vote.

Again, citizenship did not equal equality.

Mexican Labor and Disposable Membership

Federal policy treated Mexican workers as valuable when their labor was needed, especially in agriculture, railroads, and other low-wage industries. But when economic conditions changed, federal and local officials targeted Mexican communities for removal. During the Great Depression, hundreds of thousands of people of Mexican descent, including many United States citizens, were pressured, deported, or driven from the country in repatriation campaigns.

The message was unmistakable. Labor could be invited. Families could be uprooted. Belonging could become temporary when the people involved were not white.

Defining America Through Law

By the middle of the twentieth century, the United States had built two complementary systems of racial hierarchy. State governments controlled daily life through segregation, disfranchisement, criminal law, and racial violence. The federal government controlled the nation's boundaries through citizenship, immigration, territorial governance, and naturalization. Together they determined not only who possessed rights, but who belonged.

The law continued to make whiteness the preferred form of national belonging. Black Americans remained at the center of a racial caste system rooted in slavery. Asian immigrants faced exclusion. Native peoples received citizenship without full equality. Puerto Ricans and Filipinos experienced American rule without equal constitutional status. Mexican workers were welcomed when their labor was needed and expelled when they were not. The rules differed from group to group, but the purpose remained the same: preserving racial hierarchy by protecting whiteness.

Federal law did more than define citizenship. It defined the nation itself.