Image caption The so-called Peace Garden State is one of the least populous in the US

North Dakota is amending its constitution because of a long-standing technical omission that some claim makes its statehood invalid. So does that mean it's really just a US territory and not a state at all?

Every American child is taught there are 50 states in the US.

But an 82-year-old care home resident in Grand Forks, North Dakota, is throwing the truth of that universally held statement into some doubt.

While reading the state constitution, which is 40 years older than he is, John Rolczynski noticed it omitted to mention the executive branch when explaining which new officers need to take the oath supporting the US Constitution.

This, he says, makes the state constitution invalid because it is in conflict with the federal constitution, which requires all officers of the three branches of state government - executive, judicial and legislative - be bound by the oath.

The answer For 120 years, North Dakota has not fulfilled a technical requirement laid down in Article Six of the US Constitution

But its statehood is secure under Article Four, says one legal expert

Mr Rolczynski's detective work began in 1995. Sixteen years later, state senator Tim Mathern of Fargo has successfully introduced a bill to amend section 4 of article XI of the state constitution.

The amendment has been passed by the state legislature and must now be approved by the people of North Dakota at the general election in 2012.

Speaking from the care home to which he is confined with Parkinson's Disease, John Rolczynski says he feels vindicated at the end of a long campaign, in which he had even written to President Bill Clinton, but received no reply.

"It's been a long fight to try to get this corrected and I'm glad to see that it has," says the author and keen local historian.

"The amendment will be voted on in November 2012. In the interim, North Dakota is a territory."

So the US only has 49 states? Not according to one expert.

North Dakota's statehood is safe, says Cheryl Hanna, a constitutional expert at Vermont Law School, although it presents an interesting question about constitutional conflict.

It is correct, she says, that Article Six of the US Constitution requires all legislative, executive and judicial officers in the state to be bound by an oath to uphold the US Constitution.

But that condition is separate from Article Four which gives Congress power to decide when to admit a state.

North Dakota Sits in the region known as the Great Plains

Capital is Bismarck

Its largest city inspired the famous Coen brothers film, Fargo (above)

Its population of 672,591 makes it the third least populous state

Admitted to union in Nov 1889

The city of Rugby prides itself as the geographical centre of North America

"One way of looking at this is that Article Six and Article Four are distinct articles under the Constitution. Congress can approve a state under any rules that it sets and that is a separate and distinct question from whether each state has taken the right constitutional steps."

There is also the Enabling Act in 1889 under which North Dakota became a state, she says. It says in Section Four that the state constitutions should "not be repugnant to the Constitution of the United States and the principles of the Declaration of Independence".

It's clear that North Dakota's mistake does not contravene the spirit of the Enabling Act, says Ms Hanna.

"It's like a dressing oversight rather than a constitutional crisis," he says. "Congress approved North Dakota as a state, so theoretically Congress would need to take the decision to disapprove it as a state.

"I can sympathise with those wishing to escape the oppressive influence of central government, but a mistake in the North Dakota constitution is not enough to declare it an independent country. I wouldn't go remaking the US flag any time soon."

Although we might not see this as important, it's in fact important to one citizen [Mr Rolczynski] and it's important to the order of law State senator Tim Mathern

For six years, Mr Mathern has attempted to correct the constitution, although he says he was always defeated by colleagues who dismissed it as a waste of time.

"But I believe that it's important to be responsive to citizens and although we might not see this as important, it's in fact important to one citizen [Mr Rolczynski] and it's important to the order of law," he says.

It doesn't bring the statehood into question, says Mr Mathern, because the Supreme Court would rule in favour of North Dakota being a state, although it's a flaw that needs fixing.

"But for the past 120 years, we've been operating without meeting a technical requirement."

Across the state, officers take the oath every day, he says, and many from the executive branch are already doing so, despite the directive for them to do so not yet being ratified.

Unlike Texans, some of whom have long mounted a secession campaign, there are no indications that North Dakotans have any ambitions to go it alone.

However, they have long debated losing the "North" from their name, a campaign once dramatised in an episode of The West Wing.

Getting in a state Four states - Kentucky, Virginia, Pennsylvania and Massachusetts - are officially 'commonwealths'

District of Columbia is not a state

Nor is Puerto Rico, which is a territory pushing for statehood

Other states have shown much greater unrest, as recently as this week. In California, elected officials from southern and eastern parts of the state are attempting to break away and form a 51st state called South California.

In a demonstration of anger with the actions of the state government, the Riverside County Board of Supervisors voted 4-0 on Tuesday to discuss the proposal further in the autumn.

Regardless of a "hiccup" like this, North Dakota has demonstrated its worth to the US in many ways, says Sarah Walker of the State Historical Society.

"Our military presence has been a very strong asset. Many men died for their country.

"During the Spanish-American War and the Philippine insurrection, soldiers from this state fairly jumped at serving.

"One group of about 25 scouts were made up of approximately 17 North Dakotans; eight of them received the Medal of Honor for special acts of bravery."

For some, statehood is measured in deeds rather than words.