This clandestine assistance became open after the defeat of General Burgoyne at Saratoga in 1777, which demonstrated the possibility of British defeat in the conflict and led to French recognition of the colonies in February 1778. As a result of the victory of the Continental forces at Saratoga, Benjamin Franklin, who had gone to Paris as ambassador in 1776, was able to negotiate a Treaty of Amity and Commerce and a Treaty of Alliance with France. From this point, French support became increasingly significant. The French extended considerable financial support to the Congressional forces. France also supplied vital military arms and supplies, and loaned money to pay for their purchase.
French military aid was also a decisive factor in the American victory. French land and sea forces fought on the side of the American colonists against the British. At the same time, British and French (and to a lesser extent, Dutch and Spanish) forces fought for colonial wealth and empire around the world. From 1778 through 1783 -- two years after the defeat of Cornwallis at Yorktown -- French forces fought the British in the West Indies, Africa and India.
From the perspective of the American Revolution, however, the high point of French support is the landing of five battalions of French infantry and artillery in Rhode Island in 1780. In 1781, these French troops under the command of Count Rochambeau marched south to Virginia where they joined Continental forces under Washington and Lafayette. Cornwallis, encamped on the Yorktown peninsula, hoped to be rescued by the British navy. A French fleet under the command of Admiral DeGrasse intercepted and, after a fierce battle lasting several days, defeated the British fleet and forced it to withdraw. This left the French navy to land heavy siege cannon and other supplies and trapped Cornwallis on the Yorktown peninsula.
http://people.csail.mit.edu/sfelshin/saintonge/frhist.htmlIn 1785, George Washington, recently "retired to the country life," wrote a friendly letter to Carlos III, the King of Spain, thanking him for a recent gift. Washington knew that Carlos III had been generous in his support of the birth of the fledgling United States during the War of Indenpendence. For at least five years, Spain had sent more supplies and money than had been requested to help the American Rebels succeed in what must have appeared to be an impossible dream. Spanish men from the peninsula and throughout the Americas fought in the conflict.
The American Revolution used funds collected from people living in the present states of Texas, New Mexico, Arizona and California--then a part of Mexico. An important percentage of financial support originated in New Spain, now called Mexico. Eventually, thousands of Spanish troops fought British troops throughout the Americas.
http://www.neta.com/~1stbooks/vital.htmDutch Support of America's Independence 1770-1782
By Paul Trainor — 1st Continental Regt.
1770-1773 American colonists buy Dutch tea in preference to British tea.
1774 Britain declares all shipments of warlike goods to the colonies to be contraband. Local Dutch officials continue to smuggle the sinews of war to the rebellious colonists.
1776 Dutch evade British blockage of colonies by shipping goods to lesser ports enabling the flow of gun powder purchased by France to continue to Washington's army.
10/23/76 Near Philadelphia, the Andrew Doria is commissioned at Gloucester, New Jersey, as one of the first four ships in the American Navy.
11/16/76 The Andrew Doria sails into the Dutch West Indies, flying the American flag and carrying a copy of the Declaration of Independence for the Dutch Governor, Johannes de Graaff. The Dutch fire a salute appropriate to honoring the ship of an independent sovereign power. This was the first time that an American ship had received such a salute. The British government viewed this as an insult.
http://www.continentalline.org/articles/article.php?date=9503&article=950303