Counterfeiting of paper money in North America dates back to the very first emissions.  The only Massachusetts 1690 bills that survive today are raised bills; genuine bills on which the denomination was altered, or raised, to a higher denomination.  Counterfeits were a problem in all of the 13 colonies from the beginning.  Free money was the motivation for the counterfeiters was, for the first 85 years.  That all changed in 1775 when the British placed counterfeit May 10, 1775 $30 Continental bills into circulation.   

These very rare counterfeit bills represent the first tactical use of counterfeits.  The objective of the British was to undermine confidence in the paper money of the Continental Congress.  The first bills were not very convincing and were probably viewed as more of an irritation than a real threat.  The bills were printed from a relatively crudely engraved plate and are easily spotted.   As the American revolution progressed the British counterfeiting operations improved, and the counterfeit bills became a real threat to the colonial economy.  The rampant counterfeiting of the May 20, 1777 and the April 11, 1778 emissions forced the early recall of the bills, and significantly undermined confidence in the currency.  The British not only printed counterfeit bills, they encouraged the use of counterfeits by sympathizers and even issued propaganda heralding the quality and number of the counterfeits in circulation.

The pictured bill is an example of the first shot fired by the British in the economic battlefield of the American Revolution.  These are very rare counterfeits with less than 10 examples known today.  They are easily identified becuase they were printed from engraved plates, rather than typeset.  This example has evidence of mounting and paper pulls on the face, but is collectable none the less.  

Eric Newman wrote a detailed article about the British Counterfeiting Operations, the full article is available here:  https://www.britnumsoc.org/publications/Digital BNJ/pdfs/1958_BNJ_29_18.pdf