"Instead of being the best marksmen in the world and picking off every Regular that was to be seen...the continual firing which they kept up by the week and the month has had no other effect than to waste their ammunition and convince the King's troops that they are really not really so formidable."[2]See also France in the American Revolutionary War and Loyalists during the American Revolution.
The amount of support given by france was rather staggering with the French troops outnumbering both British and American troops at the siege of Yorktown!
French: 11,800 regulars, 29 war ships
American: 5,700 regulars 3,100 militia
British: 9,000 soldiers
Hessians were a different thing.
Hessians comprised approximately one-quarter of the British forces in the Revolution. They were called Hessians, because 16,992 of the total 30,067 men came from Hesse-Kassel. Some were direct subjects of King George III, even though they were not British, since he ruled them as the Elector of Hanover. Other "Hessian" soldiers were sent by Count William of Hesse-Hanau; Duke Charles I of Brunswick-Wolfenbüttel; Prince Frederick of Waldeck; Margrave Karl Alexander of Ansbach-Bayreuth; and Prince Frederick Augustus of Anhalt-Zerbst.
About 18,000 Hessian troops arrived in the Thirteen Colonies in 1776, with more coming in later. They first landed at Staten Island on August 15, 1776, and their first engagement was in the Battle of Long Island. The Hessians fought in almost every battle, although after 1777 they were mainly used as garrison troops. An assortment of Hessians fought in the battles and campaigns in the southern states during 1778–80 (including Guilford Courthouse), and two regiments fought at the Siege of Yorktown in 1781.
The troops were not mercenaries in the modern sense of military professionals who voluntarily hire out their own services for money. As in most armies of the eighteenth century, the men were mainly conscripts, debtors, or the victims of impressment; some were also petty criminals. Pay was low; some soldiers apparently received nothing but their daily food. The officer corps usually consisted of career officers who had served in earlier European wars. The revenues realized from the men's service went back to the German royalty. Nevertheless, some Hessian units were respected for their discipline and excellent military skills.
The real rub comes since use of Hessian troops by the British further rankled American sentiment, and pushed some loyalists to be in favor of the revolution. Using foreign troops to put down the rebellion was seen as insulting, as it treated British subjects no differently than non-British subjects; Some pro-British Tories felt that the British nature of Americans should have entitled them to be above mercenary forces.
The problem was that many of the Loyalist Officers depended on local support to fill the ranks of the Loyalist units. So, I find it annoying that someone who claimed loyalty to the crown would not come forth and do their duty. Moreover it was their duty to serve in Loyalist units if they were insulted by the use of Hessians. This is one of the reasons for the reputation the loyalists had for being cowardly.
If you consider that the War for American Independence was a civil war to begin with, this would be roughly like the US Forces expecting some other power to come to their rescue.
Nevermind, that the forces of rebellion needed the help of the French to defeat the British.