So has it ever been been paid.

Well it has been paid off before, The answer is yes it has.
James Swan

U.S. Debt and Foreign Loans, 1775-1795 During the American Revolution, a cash-strapped Continental Congress accepted loans from France. Paying off these and other debts incurred during the Revolution proved one of the major challenges of the post-independence period. The new U.S. Government attempted to pay off these debts in a timely manner, but the debts were at times a source of diplomatic tension.

In order to pay for its significant expenditures during the Revolution, Congress had two options: print more money or obtain loans to meet the budget deficit. In practice it did both, but relied more on the printing of money, which led to hyperinflation. At that time, Congress lacked the authority to levy taxes, and to do so would have risked alienating an American public that had gone to war with the British over the issue of unjust taxation.

The French Government began to secretly ship war materiel to the American revolutionaries in late 1775. This was accomplished by establishing dummy corporations to receive French funds and military supplies. It was unclear whether this aid was a loan or a gift, and disputes over the status of this early assistance caused strong disagreement between American diplomats in Europe. Arthur Lee, one of the American commissioners in France, accused another, Silas Deane, of financial misdealings, while the third member of the commission, Benjamin Franklin, remained aloof. Lee eventually succeeded in convincing Congress to recall Deane. The early French aid would later resurface as one of the disputes behind the 1797 XYZ Affair that led to the Quasi-War with France.

During the Revolution, the French Government also provided the Americans with loans, eventually totaling over two million dollars, most of which were negotiated by Benjamin Franklin. John Adams also secured a loan from Dutch bankers in 1782. After fighting between the Americans and the British ended in 1783, the new U.S. Government established under the Articles of Confederation needed to pay off its debt, but lacked sufficient tax authority to secure any revenue. The government struggled to pay off the loans, stopping payments of interest to France in 1785 and defaulting on further installments that were due in 1787. The United States also owed money to the Spanish Government and private Dutch investors, but focused on paying off the Dutch because Amsterdam remained the most likely source of future loans, which the United States successfully obtained in 1787 and 1788, despite its precarious financial state.

Under the U.S. Constitution of 1789, the new federal government enjoyed increased authority to manage U.S. finances and to raise revenues through taxation. Responsibility for managing debts fell to Secretary of the Treasury Alexander Hamilton. Hamilton placed U.S. finances on firmer ground, allowing for the U.S. Government to negotiate new loans at lower interest rates. In addition, the United States began to make regular payments on in its French debts starting in 1790, and also provided an emergency advance to assist the French in addressing the 1791 slave revolt that began the Haitian revolution.

Although the federal government was able to resume debt payments, total federal expenditures exceeded revenues during many years in the 1790s. Hamilton therefore sought additional loans on Dutch capital markets, although the improved U.S. financial situation made these loans easier to obtain. These private loans from Dutch bankers also helped pay off loans owed to the Spanish Government, back pay owed to foreign officers, and U.S. diplomatic expenses in Europe.

In 1795, the United States was finally able to settle its debts with the French Government with the help of James Swan, an American banker who privately assumed French debts at a slightly higher interest rate. Swan then resold these debts at a profit on domestic U.S. markets. The United States no longer owed money to foreign governments, although it continued to owe money to private investors both in the United States and in Europe.

Although U.S. finances had been shaky under the Articles of Confederation, the United States was able to place itself on a sound financial footing during the 1790s. This enabled it to preempt diplomatic embarrassment and dependence on foreign powers during that period, and also improved U.S. credit on European capital markets, which enabled the U.S. Government to obtain low-interest loans for the Louisiana Purchase in 1803.

Federal debt And president Andrew Jackson
See also: Panic of 1837 In 1835, Jackson managed to reduce the federal debt to only $33,733.05, the lowest it has been since the first fiscal year of 1791.[17] However, this accomplishment was short lived, and a severe depression from 1837 to 1844 caused a ten-fold increase in national debt within its first year.[18]

Abraham Lincoln

During the Civil War (from 1861-1865), President Lincoln needed money to finance the War from the North.  The Bankers were going to charge him 24% to 36% interest.  Lincoln was horrified and went away greatly distressed, for he was a man of principle and would not think of plunging his beloved country into a debt that the country would find impossible to pay back.
Eventually President Lincoln was advised to get Congress to pass a law authorizing the printing of full legal tender Treasury notes to pay for the War effort.  Lincoln recognized the great benefits of this issue.  At one point he wrote:
"... (we) gave the people of this Republic the greatest blessing they have ever had - their own paper money to pay their own debts..."
The Treasury notes were printed with green ink on the back, so the people called them "Greenbacks".
Lincoln printed 400 million dollars worth of Greenbacks (the exact amount being $449,338,902), money that he delegated to be created, a debt-free and interest-free money to finance the War.  It served as legal tender for all debts, public and private.  He printed it, paid it to the soldiers, to the U.S. Civil Service employees, and bought supplies for war.
Shortly after that happened, "The London Times" printed the following
"If that mischievous financial policy, which had its origin in the North American Republic, should become indurated down to a fixture, then that Government will furnish its own money without cost.  It will pay off debts and be without a debt.  It will have all the money necessary to carry on its commerce.  It will become prosperous beyond precedent in the history of the civilized governments of the world.  The brains and the wealth of all countries will go to North America.  That government must be destroyed, or it will destroy every monarchy on the globe."
The Bankers obviously understood.  The only thing, I repeat, the only thing that is a threat to their power is sovereign governments printing Interest-free and debt-free paper money.  They know it would break the power of the international Bankers.
In retaliation

After this was published In "The London Times", the British Government, which was controlled by the London and other European Bankers, moved to support the Confederate South, hoping to defeat Lincoln and the Union, and destroy this government which they said had to be destroyed.
They were stopped by two things. First, Lincoln knew the British people, and he knew that Britain would not support slavery, so he issued the Emancipation Proclamation, which declared that slavery in the United States was abolished.  At this point, the London Bankers could not openly support the Confederacy because the British people simply would not stand for their country supporting slavery.
Second, the Czar of Russia sent a portion of the Russian navy to the United States with orders that its admiral would operate under the command of Abraham Lincoln.  These ships of the Russian navy then became a threat to the ships of the British navy which had intended to break the blockade and help the South.

The North won the War, and the Union was preserved.  America remained as one nation.
Of course, the Bankers were not going to give in that easy, for they were determined to put an end to Lincoln's interest-free, debt-free Greenbacks.  He was assassinated by an agent of the Bankers shortly after the War ended.
Thereafter, Congress revoked the Greenback Law and enacted, in its place, the National Banking Act.  The national banks were to be privately owned and the national bank notes they issued were to be interest-bearing.  The Act also provided that the Greenbacks should be retired from circulation as soon as they came back to the Treasury in payment of taxes.
In 1972, the United States Treasury Department was asked to compute the amount of interest that would have been paid if that 400 million dollars would have been borrowed at interest instead of being issued by Abraham Lincoln.  They did some computations, and a few weeks later, the United States Treasury Department said the United States Government saved 4 billion dollars in interest because Lincoln had created his own money.  So you can about imagine how much the Government has paid and how much we owe solely on the basis of interest.