How Many States Are in the USA?

50. That part is not in dispute — but it is younger than it looks. The United States has had 50 states only since 1959. For the 47 years before that, the correct answer was 48.

“50” feels permanent, the way a national fact should. But it is really the current value of a number that climbed steadily for 172 years — from the original 13 states to the 50th — and then stopped. Unlike the count of countries in Europe, there is no argument about the figure itself. The interesting thing about 50 is not whether it is right. It is how recently it became right, and whether it will stay that way.

Below: a timeline you can drag through to watch states join one by one, and a game that tests whether you can name a state from its outline alone.

For 47 years, the answer was 48

New Mexico and Arizona were both admitted in 1912, completing the contiguous block of states between Canada and Mexico. From that January until 1959, the United States had exactly 48 states — long enough that the 48-star flag flew over both world wars and was the only flag two generations of Americans had ever known. Anyone who learned “48 states” in school in, say, 1940 was learning a fact that would later be quietly retired.

The two states that made it 50

Alaska was admitted on January 3, 1959, and Hawaii on August 21 of the same year, both signed in by President Dwight D. Eisenhower. The 50-star flag was designed not by a government office but by Robert G. Heft, a 17-year-old junior at Lancaster High School in Ohio, as a 1958 history-class project — he added two stars to a 48-star flag on a hunch that Alaska and Hawaii were coming. His teacher gave it a B-minus and challenged him to get it adopted. After Heft lobbied Washington for two years, his design was chosen; it became the official flag on July 4, 1960, and the teacher changed the grade to an A.

The count climbed for 172 years

Statehood was not a steady drip. The fastest stretch came in November 1889, when North Dakota, South Dakota, Montana and Washington were all admitted within days of one another under a single law, the Enabling Act of 1889 — four new stars in one week. The oddest addition was West Virginia, which in 1863 broke away from Virginia during the Civil War, the only state ever carved out of an existing one in wartime. Drag the timeline above across the 1880s and 1860s and those bursts are visible as the number jumps.

What “50” quietly leaves out

“How many states” and “how much of America” are not the same question. Alongside the 50 states, the United States governs the District of Columbia and five permanently inhabited territories — Puerto Rico, Guam, the U.S. Virgin Islands, American Samoa and the Northern Mariana Islands. More than three million people live in them, the large majority in Puerto Rico, and they have no vote for president and only non-voting delegates in Congress. They are part of the country; they are simply not states.

Could it still change?

The plateau is not guaranteed to last. A Washington, D.C. statehood bill passed the U.S. House of Representatives in 2020 and again in 2021, though it was not taken up by the Senate. Puerto Rico has held a run of status referendums — in 2012, 2017, 2020 and 2024 — with statehood drawing majority or plurality support each time, amid disputes over turnout and boycotts. Heft himself saw it coming: after his 50-star design, he drew up a 51-star version too. Whether it is ever needed is a political question, not a settled one.

Fifty is not really a fact about the United States. It is the year 1959, still holding.

Can you name them by shape?

You have watched all 50 join. Here is the harder test: sixteen US states shown as outlines only, five names to choose from each time. Some are unmistakable; a few are trickier than you would expect.