It is full membership in the nation, the status that carries the right to vote and the duties of civic life. For most of American history, the hardest question has been who gets to have it.
Citizenship is the legal status of being a full member of a nation, carrying both rights, like voting and protection, and responsibilities, like jury duty and obeying the law. The word traces to the Latin civis, a member of a city or political community.
America has two main paths to it. Birthright citizenship, guaranteed by the Fourteenth Amendment, makes nearly everyone born on US soil a citizen automatically. Naturalization makes citizens of foreign-born people who choose and qualify for it.
Who counted as a citizen was long and bitterly contested. The infamous Dred Scott decision of 1857 held that Black Americans could never be citizens. The Fourteenth Amendment, in 1868, overturned that directly, declaring all persons born or naturalized in the United States to be citizens.
Citizenship and the vote are linked but not identical. For much of history, citizens could be barred from voting by race, sex, or wealth. The expansion of who could vote, even among citizens, was a separate, century-long struggle.