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“When they say it’s not about race and partisanship,” said Virginia Democratic Rep. Gerry Connolly, “you can be sure it’s about race and partisanship.” He was speaking to his Republican opponents in last month’s congressional hearing on whether D.C. should be granted statehood with full representation. But he could have been describing the majority of debates over statehood dating back to the country’s founding.

The September hearing marked the first time the House took up the question of D.C. statehood in 25 years. It’s been an uphill climb even to get to this point. The clean, even rows of 50 stars on the flag often seem immutable. But the union as we know it did not simply spring from some noble constitutional wellspring. Debates over statehood have always been a messy, lurching process in which Americans argue over what kind of country they want.

There were concerns in the original 13 states about the sort of element that potential new states would introduce into the American population. Easterners “would look at frontier people as the ‘great unwashed’—semi-barbarous savages,” Peter Onuf, a historian at the University of Virginia and author of the book Statehood and Union, told me. “The idea of letting in too many Westerners was the equivalent of letting too many immigrants in now if you’re a nativist.”

But the economic opportunities, as well as concerns that the newly independent nation was vulnerable to foreign powers if it remained East Coast–bound, made westward expansion too tempting to resist.

Some legal framework had to be devised for incorporating the new territories into the country. In 1787, the Northwest Ordinance established governance for what had been the British colonial territories north of the Ohio river—what is now the states of Ohio, Indiana, Illinois, Michigan, Wisconsin, and parts of Minnesota. The ordinance laid out a method by which the new states in the territory would gradually be admitted into the union in the decades to come, first as territories without full representation in Congress, then as states. This method would be repeated with most—though not all—other states, as the country spread West, acquiring new territory via war and treaty with European powers while pushing native peoples off their lands.

Race has persisted as the chief concern in defining the union.

The ordinance also anticipated the Constitution, which would be written a short time later, with a bill of rights for the new territories that forbade slavery in the new states.

The fight between pro-slavery and free states for power in Washington dominated union expansion debates throughout the early 19th century. Most famously the Missouri Compromise of 1820 added Maine—formerly a territory of Massachusetts—to the union to counterbalance the new slave state of Missouri and set a border between slave and nonslave state territory for the new states that were to be carved out of the Louisiana Purchase.

Long after slavery was abolished, race has persisted as the chief concern in defining the union.

By the end of the 19th century, the U.S. had also started to acquire an overseas empire—purchasing Alaska in 1867, annexing Hawaii in 1898, and taking sovereignty over Puerto Rico, Guam, and the Philippines during the Spanish-American War that same year.

The relatively rapid influx of foreign territories threatened the racial balance of power. Until this point, the U.S. government considered territories and those within them to have full protection of the Constitution. So the Supreme Court cases drew a new line in a series of early 20th century cases known as the Insular Cases, which distinguished between “incorporated” and “unincorporated” territories. The Constitution only applied fully in the former, which included Hawaii and Alaska—because they had been granted constitutional rights in Congress—but not in Puerto Rico, Guam, the Virgin Islands, or American Samoa. The justices didn’t mince words about what they saw as the danger of providing full citizenship rights to “uncivilized races” for whom governance by “Anglo-Saxon principles may for a time be impossible.”

Residents of the U.S. territories—with the complicated exception of American Samoa—would eventually attain citizenship, though the legacy of the legal doctrine that holds these territories as less than fully American remains, giving Congress say over laws passed in the territories.

For decades, there was still stiff opposition preventing Hawaii and Alaska from becoming fully empowered states. Hawaii’s multicultural population and Alaska’s large number of indigenous residents generated the predictable racial fearmongering. Historian Claus-M. Naske writes, “[A] common inquiry in private conversation about Hawaiian statehood was a whispered ‘how would you like to have a United States Senator called Moto?’ ”

“Something of the same division that tore the country apart works against the admission of both Hawaii and Alaska,” the prominent columnist Marquis Childs observed in 1956. “Racial prejudice coincides with certain powerful economic interests to insure a roadblock big enough … to hold it back.”

There were worries admitting states not connected to the continental United States would “set an undesirable precedent, opening the door to statehood for such lands as the Philippines, Guam and Okinawa,” Naske writes in the book Alaska: A History of the 49th State.

Cold War paranoia also played a role. “If Hawaii becomes a state, it will be dominated by Communist influences … it will serve as a beachhead for Communist infiltration,” argued Rep. B. Carroll Reece, noting the influence of the left-wing Longshoremen’s Union on the state’s politics. Senate Majority Leader Mitch McConnell echoed a similar warning that the push for D.C. and Puerto Rico statehood is a part of an agenda for “full-bore socialism.” The Hawaii statehood commission countered with a pamphlet titled, “Hawaii, U.S.A.: Communist Beachhead or Showcase for Americanism?”

Partisanship and race intertwined. Alaska “had been generally Democrat, and numerous members worried that two new Democrat senators would jeopardize their determination to prevent any civil rights legislation,” says Stephen Haycox, emeritus professor of history at the University of Alaska Anchorage. “The antidote to that would be the admission of Republican Hawaii soon after Alaska.”

In 1955, “sorely tried through 88 years of step-childhood,” Alaskan statehood advocates held a convention in Fairbanks to write a constitution for their aspirational state. Former Gov. and lifelong statehood advocate Ernest Gruening opened the meeting with a barnburner of a speech titled, “Let Us Now End American Colonialism.”

Pointing out that “our nation was born of revolt against colonialism,” Gruening continued:

What more ironical, then, what more paradoxical, than that [our nation] maintains Alaska as a colony? What could be more destructive of American purpose in the world? And what could be more helpful to that mission of our nation than to rid America of its last blot of colonialism by admitting our only two incorporated territories—Alaska and Hawaii—to the equality they seek, the equality provided by the long-established and only possible formula, namely statehood?

Ultimately, it benefited the statehood candidacies of both Alaska and Hawaii that they came as a package deal, canceling each other out from a partisan point of view, though ultimately Hawaii would become staunchly Democratic and Alaska Republican.

Since Alaska and Hawaii finally became states in 1959, the U.S. has been in its longest period without a new state since the country was founded. Part of the reason for this is geographical. Nearly all American territory has been divided into states, and countries almost never acquire new territory anymore. Writer Doug Mack has argued in Slate that the legacy of the Insular Cases has also played a role, preventing overseas territories from acquiring statehood as Alaska and Hawaii did.

There’s no imminent movement in the stalemate over D.C. and Puerto Rico, but there are some signs it won’t last forever. Political momentum behind statehood for Puerto Rico has grown, particularly following the Trump administration’s indifferent response to the devastation of Hurricane Maria. (Results of the last referendum held on the question in 2017 were a little ambiguous, with opponents of statehood boycotting over the question’s wording.)

D.C. voters overwhelmingly backed statehood in a 2016 referendum. The District’s nonvoting congressional delegate, Eleanor Holmes Norton, introduces a statehood bill every year, but this year it boasts 219 co-sponsors in the House—all Democrats.

Statehood proponents point out that the district has a larger population—more than 700,000—than Wyoming and Vermont, yet its residents are denied full representation in Congress, an update of Gruening’s exhortation that “We suffer taxation without representation, which is no less ‘tyranny’ in 1955 than it was in 1775.” In D.C.’s case, as Connolly noted, it’s hard to ignore the fact that representation is being denied to a majority-minority population that’s 47 percent black.

Listen to Christina Cauterucci interview activist Wade Henderson about the D.C. statehood movement on What Next.

Still, Democrats would need sweeping majorities in Congress in order to approve legislation that would effectively add four new Democratic senators. Unlike with Hawaii and Alaska, there is no clear political counterweight to D.C. and Puerto Rico.

Today, America is a rapidly urbanizing country with a political system that still awards disproportionate legislative and electoral power to rural voters. Where better to have a conversation about that issue than in a debate over the status of a city whose 700,000 residents are denied full citizenship rights because of where they live? It’s also an increasingly racially and linguistically diverse country led by a president devoted to preserving a narrow, racist vision of Americanness. Where better to have a conversation about that than in a debate over the status of a Spanish-speaking island subject to a history of marginalization, imperialism, and official racism?

The American frontier may be closed, but there are still citizens awaiting admission. And there are still conversations America needs to have about itself.