Paying off the bonds that the federal government had used to borrow money during the revolution at full

value was controversial because

Paying the bonds that the federal government used during the revolution was controversial because the nation had a $75 million total debt and could not decide how to pay for it.

Explanation:

The US owed $75 million, $10 million of which were used to finance the American revolution were owed to France and other nations. The US faced the dilemma of paying the war bonds wither at the current market value or at the higher original market value. Hamilton passed the controversial "report of national credit of 1790" which advised paying off the full debt by implementing a excise tax on whiskey and tariff on all goods that were imported.  

it's no easy i swear it's hard