All the States That Were Once Independent Countries Before Joining the U.S.

Most Americans learn that the 50 states joined the Union one by one. What the textbooks skip is that some of them didn’t just join – they surrendered. Four U.S. states existed as fully independent nations before becoming part of the United States. One was a kingdom recognized by the major powers of Europe. One fought a war to earn its independence. One governed itself for 14 years while the young United States refused to even acknowledge it existed. And one declared independence on a Tuesday and was absorbed by the U.S. military before the month was out.

Here are all four, ranked from the longest to the shortest run as an independent nation.

Hawaii

No American state has a more dramatic path to statehood than Hawaii – and no annexation in U.S. history is more contested.

The Hawaiian Kingdom was founded in 1795 when Kamehameha I, a powerful chieftain from the Big Island, conquered the islands of Oahu, Maui, Molokai, and Lanai through a combination of military genius and superior firepower – including Western cannons. By 1810, when the remaining islands of Kauai and Niihau voluntarily joined, the entire Hawaiian archipelago was unified under one government for the first time in history.

What followed was nearly a century of genuine sovereignty. The Kingdom of Hawaii established diplomatic relations with the United States, France, Britain, and other major powers. It adopted a written constitution in 1840, created a bicameral legislature, and minted its own currency – the Hawaiian dollar. European monarchs exchanged formal correspondence with Hawaiian kings. The kingdom was, by every international standard, a real country.

That ended on January 17, 1893. Queen Liliʻuokalani, the final monarch, attempted to restore royal authority that had been stripped by American sugar planters and businessmen years earlier. The response was swift and brutal: a group calling itself the Committee of Safety – composed mostly of American settlers and their descendants – staged a coup. U.S. Marines from the USS Boston landed in Honolulu, not to stop the coup, but to support it. The queen surrendered to avoid bloodshed, explicitly under protest, and specifically noting that she was yielding to the superior military force of the United States.

Five years later, the U.S. annexed Hawaii outright. It became a territory in 1900 and a state in 1959. In 1993, the U.S. Senate passed the Apology Resolution, formally acknowledging that “the overthrow of the Kingdom of Hawaii occurred with the active participation of agents and citizens of the United States” and that Native Hawaiians “never directly relinquished their claims to their inherent sovereignty.” A Hawaiian sovereignty movement continues to this day.

Vermont

Vermont spent 14 years as an independent republic – and the United States government refused to acknowledge it the entire time.

The conflict began with a land dispute. After the French and Indian War, both New Hampshire and New York claimed the territory that would become Vermont, issuing competing land grants to settlers. King George III settled the dispute in 1764 by awarding it to New York – but the settlers who’d received New Hampshire grants weren’t interested in switching allegiances. Led by the legendary Ethan Allen and his Green Mountain Boys militia, they spent years physically preventing New York surveyors from entering the region.

When the Revolution broke out, Vermont saw its opportunity. On January 15, 1777, delegates from 28 towns declared independence – not just from Britain, but from New York and New Hampshire as well. They established the Republic of Vermont with its own constitution, governor, legislature, postal system, and currency (the Vermont copper, stamped with the Latin phrase Vermontis Res Publica – Republic of Vermont).

Their constitution made Vermont the first government in North American history to explicitly ban adult slavery – a full 86 years before the Emancipation Proclamation.

The United States refused to admit Vermont to the Union for one simple reason: New York objected. If Vermont was recognized, New York’s territorial claims evaporated. So Vermont governed itself independently for 14 years, without a seat in Congress and without diplomatic recognition from any foreign power. At one point, Vermont secretly negotiated with British Canada about potentially rejoining the British Empire – a bargaining chip they used to pressure the Continental Congress.

When the British surrendered at Yorktown in 1781, Vermont’s leverage vanished. The republic spent another decade in diplomatic limbo until New York finally dropped its objections. Vermont entered the Union on March 4, 1791, as the 14th state. The constitution and laws of the Republic of Vermont simply continued in effect – the most seamless national-to-state transition in American history.

Texas

The Republic of Texas is the most famous of America’s former independent nations – and with good reason. It won its independence in one of the most dramatic military reversals in history, survived a decade of financial ruin and border wars, and was recognized as a sovereign country by the United States, France, Britain, the Netherlands, and Belgium.

It started at the Alamo.

American settlers in Mexico’s Texas territory had grown increasingly hostile to the central government in Mexico City, particularly after General Antonio López de Santa Anna dissolved the federal system and centralized power in 1835. War broke out in October 1835. On March 6, 1836, Santa Anna’s army killed every defender at the Alamo – 189 men who had held the mission for 13 days. Four days earlier, Texas had formally declared independence.

The Alamo bought just enough time. On April 21, 1836, General Sam Houston led a surprise attack on Santa Anna’s forces at San Jacinto, routing the Mexican army in just 18 minutes. Santa Anna was captured the next day. Under duress as a prisoner, he signed the Treaties of Velasco recognizing Texas independence. Mexico later repudiated the treaty – claiming it was signed under coercion – and never officially recognized the Republic of Texas during its entire existence, maintaining it was simply a rebellious province.

For nearly ten years, the Republic of Texas operated as a struggling but functioning nation. It had a president (Sam Houston served two non-consecutive terms), a congress, a navy, an army, foreign embassies, and its own currency – the Texas dollar, which suffered from rampant inflation. The republic was perpetually broke, constantly harassed by Mexican forces along its southern border, and embroiled in conflicts with Comanche and other Native nations to the north.

Texas was annexed by the United States on December 29, 1845. The formal transfer of power happened February 19, 1846. True to form, the annexation immediately triggered the Mexican-American War.

California

California’s run as an independent nation was so brief that most of its citizens probably didn’t know it had ended before it was already over.

On June 14, 1846, a group of 33 American immigrants in the Mexican territory of Alta California seized the town of Sonoma and declared the California Republic. They raised a handmade flag featuring a grizzly bear and the words “California Republic.” Their grievances were real: Mexican authorities had threatened to expel American settlers from the territory, and many had been denied the right to buy or rent land. The rebels elected military officers, declared independence from Mexico, and waited to see what would happen next.

What happened next was that the Mexican-American War was already underway – it had started weeks earlier, though word hadn’t reached the settlers yet. U.S. Army Captain John C. Frémont, who was in the area with a military surveying party, had been quietly encouraging the rebellion behind the scenes. When the U.S. Navy arrived at Monterey on July 7, 1846, Commander John Sloat raised the American flag and claimed California for the United States. Two days later, on July 9, U.S. Navy Lieutenant Joseph Revere rode into Sonoma and replaced the Bear Flag with the Stars and Stripes. The California Republic ceased to exist – 25 days after it was declared.

It’s worth noting what the California Republic actually was and wasn’t. It was never recognized by any nation, including the United States. It never established a civil government – no president, no legislature, no courts, no laws. It controlled only a small area around Sonoma County, not the entire territory of California. Most historians characterize it as an armed rebellion rather than a genuine nation-state.

And yet. The Bear Flag that flew over Sonoma for 25 days became the basis for California’s official state flag, which still features that grizzly bear today. The episode is taught in California schools and celebrated in California history. Sometimes 25 days is enough to leave a permanent mark.

Four states. One empire-ending queen. One militia that threatened to join the British. One broke, battle-hardened republic. And one rebellion that was technically over before most people heard about it.