As we know from our history books, the War for Independence began with the shots fired at Lexington and Concord. Those shots required gunpowder, a substance that was in short supply throughout the colonies. In 1775 there was only one American gunpowder mill, the Frankford Mill in Pennsylvania, and it was turning out a miniscule amount compared to what would be needed to wage a successful war. In addition, this mill was not turning out the high-quality powder needed for artillery use. If the Patriots were going to have any chance of victory, the colonies needed to step up production or import it. Had it not been for the French assistance in supplying the Americans with gunpowder from 1776 throughout the war, American forces would not have been able to fight and win the battles that they did.
Gunpowder is a mixture of sulfur, charcoal, and potassium nitrate that must be combined in specific ratios. While this sounds simple enough, it must be remembered that in 1775 the state of chemistry was rudimentary. Potassium nitrate itself is a compound of nitrogen and potassium, neither element of which had been identified at that point in time. What they did know was that what they called “nitre” was needed, which, in some recipes, involved soaking soil in urine from both animals and humans, and then allowing it to dry. The dried urine-soil was then boiled to produce saltpeter. Not all recipes agreed with this method which added to the problems in making gunpowder. Unfortunately this required half a year or more to produce nitre-bearing soil and created a bottleneck in the production of gunpowder in America.
When the War for Independence started American supplies of powder were what they had gathered from Royal sources or their own local supplies. The amount was not enough to sustain an army in the field. While Congress was hopeful that they could establish enough mills to create their own self-sustaining sources of gunpowder, they also decided to seek additional supplies from overseas which meant European suppliers. The Journals of the Continental Congress are full of references to purchasing gunpowder in the West Indies. To do so meant selling American goods which involved adjusting the rules under the Association agreement of 1774. As several congressional delegates noted, gunpowder was needed or else the whole enterprise was lost. A Secret Committee was set up on September 19, 1775 to contract and agree to importation of gunpowder not to exceed 500 tons. In addition, saltpeter and sulfur could be bought to make up part of the 500 tons.
This illustrated just how desperate the Continental Congress was for gunpowder as well as the poor state of affairs in gunpowder manufacturing in the colonies. It also brings us to a question about why gunpowder manufacturing was so miniscule for colonies that had been involved in a series of wars between Great Britain and France for almost a century as well as an on-and-off-again conflict with Native Americans along the frontiers. The first known colonial powder mill was mentioned in an order of the General Court of Massachusetts on June 6, 1639. Then as it was during the Revolution, the production of saltpeter was recognized as a barrier to gunpowder manufacturing. Steps were taken to alleviate that situation and small scale gunpowder manufacturing were in operation throughout the remainder of that century and the 18th until the Seven Year’s War.
The burgeoning trade between Great Britain and her colonies in North America that flourished from the 1750s onward apparently included gunpowder as one commodity that was cheaper to make in Britain than in the colonies. France found her gunpowder manufacturing had slipped as well by 1774, partly due to the importation of cheap saltpeter from India, a trade controlled by Great Britain. Fortunately for the French and later the Americans, Antoine Lavoisier was appointed to head France’s Gunpowder Commission where his recommendations quickly brought France back to full production of both gunpowder and saltpeter. Saltpeter again was the key ingredient for both nations. Trade with the American colonies was controlled by Britain through the Navigation Acts and industrial production discouraged by various laws. One of the results of this was that the colonists allowed their powder mills to decay and closed them as it was far more convenient and cost effective to import gunpowder from Britain. The result would be that the colonies found themselves in dire need of powder mills in 1775.
Due to the nature of the colonial governments and their relationship with the Continental Congress, it was felt by many that gunpowder production was something left to the state governments. At first production was renewed and several thousand pounds produced, but the lack of available saltpeter quickly throttled back production. Only the arrival of imported saltpeter allowed some mills to continue production, but that varied on what ports the saltpeter arrived in as well as the difficulty in obtaining contracts from Congress, who was purchasing most of the saltpeter. In addition, the quality of the gunpowder from these hastily erected mills ranged over a wide margin. In Massachusetts both Generals William Heath and George Washington noted the poor quality of that gunpowder. The result was one which would last throughout the entire war, that of a persistent demand for gunpowder which would never be met by domestic production at any point in the conflict.
The shortage of powder was felt early in the conflict; one factor (not necessarily a main one) in the British victory at Bunker Hill on June 17, 1775 was the limited amount of gunpowder possessed by the Patriot forces. In late April, General Artemas Ward, commander of the Massachusetts Bay forces besieging Boston, had taken stock of the powder in his army’s control and found it to be woefully short prompting that colony’s Committee of Safety to request gunpowder from the towns and villages. This situation improved, but in August another inventory ordered by George Washington found supplies to be so short that only a half pound per man could be furnished. Gen. John Sullivan said that Washington on hearing of this report did not utter a word for half an hour. Requests were sent to colonial governments for gunpowder which arrived in short order. We can only speculate on what might have happened had the British made an attempt to break the siege before that critical shortage of gunpowder was eased.
Desperate for powder, no matter where it was located, both Washington and Congress eyed the British powder magazine on the island of Bermuda. Unbeknownst to each other both undertook separate operations to seize the powder. Governor Bruere of Bermuda described the raid organized by Congress on the powder magazine as follows:
I had less suspicion than before, that such a daring and Violent attempt would be made on the Powder Magazine, which in the dead of night of the 14th of August was broke into on Top, just to let a man down, and the Doors most Audaciously and daringly forced open, at the great risk of their being blown up; they could not force the Powder Room Door, without getting into the inside on Top. They Stole and Carried off about one Hundred Barrels of Gun powder, and as they left about ten or twelve Barrels, it may be Supposed that those Barrels left, would not bare remooving. It must have taken a Considerable number of People; and we may Suppose some Negroes, to assist as well as White Persons of consequence…
The next morning the 15th instant (of August), one sloop Called the Lady Catharine, belonging by Her Register to Virginia, George Ord Master, bound to Philadelphia, was seen under Sail, but the Custom House Boat could not over take Her.
The “Negroes” and “White Persons of consequence” the governor referred to were people on the island of Bermuda who assisted the Americans steal the powder. The ship sent by Washington arrived weeks later only to find the powder gone.
The campaign in Canada, threats along the western frontier from Native Americans, the looming expectation of a major British attack at New York, and the needs of naval forces all meant that even more gunpowder would be needed. The new powder mills would fall short of expected needs in 1776 and as the initial supplies of saltpeter ran low, only imported amounts allowed the mills to produce any real supplies of gunpowder at all. While sources disagree on the percentage of powder produced by these mills during this period compared to imported amounts, they do agree that without imported or captured gunpowder the Continental Army would have run out several times during that year’s campaigns. This situation was made dire by the loss of supplies at Forts Washington and Lee in New York in November of 1776 where over 400,000 rounds of ammunition were captured at Fort Lee alone.
Fortunately for the American cause, interests in Europe were such that aiding the Americans was seen by several nations as a means to weaken Great Britain. The Dutch were more than happy to trade with American ships at St. Eustatia throughout the conflict until the British attacked and captured the island in 1781. Gunpowder from Europe, mainly French, transferred hands and was sent to America as well as saltpeter. Prior to the French agreeing to supply clandestine aid to the Americans, enterprising French merchants had already arranged to ship large quantities of arms and gunpowder through the West Indies despite the obvious violations of international law. The various colonial legislatures had also been busy arranging for gunpowder purchases as well. This was fortuitous because the large losses by the Continental Army left little available for the colonial militias.
The clandestine aid from France arrived at a time when it was desperately needed. The powder mills in the colonies began to run out of saltpeter in 1777 and production fell abruptly. Silas Deane, the Continental Congress’s representative in France served as a middleman and arranged for the shipment of almost a million pounds of gunpowder. Washington’s shortage of gunpowder had led him to issue orders prohibiting its wastage in 1775 and he had to repeatedly reissue similar orders throughout the war despite the French supplies of gunpowder. Estimates place the percentage of French supplied arms to the Americans in the Saratoga campaign up to 90%, but the gunpowder used was for all practical purposes supplied by the French entirely. The critical shortage of gunpowder played a major role in the continued stalemate in the north in 1780 as General Knox’s estimates of the powder needed for a siege of New York City was more than the Continental Army could reasonably expect to have available that year.
The inability of the Americans to manufacture an adequate supply of gunpowder was just one of the many critical problems the rebels faced during the Revolutionary War. Domestic production, though promising at first, never came close to fulfilling their needs. This shortage created a situation that necessitated an American search for foreign supplies as well as revealing the necessity of foreign aid. Fortunately, the conflict between Great Britain and her rebellious colonies created a situation that other nations, particularly France, exploited in order to hurt Britain’s place in the balance of power. Had it not been for the French assistance in supplying the Americans with gunpowder from 1776 throughout the war, American forces would not have been able to sustain their war effort and win the battles that they did, and ultimately the war and independence.
 J.L. Bell, “How Not to Make Saltpetre,” Boston 1775, April 3, 2013. http://boston1775.blogspot.com/search/label/gunpowder (accessed August 9, 2013).
 Letter Governor Bruere to Lord Dartmouth, August 17, 1775 and September 13, 1775. William Bell Clark, editor, Naval Documents of the American Revolution, vol. 1 and vol. 2, (Washington, DC: U.S. Navy Department, 1964, 1966), 91.