The Americans still held New York, the right bank of the Hudson; but their flank was dangerously threatened, and Washington, true to his policy, preferred the damaging loss of New York to the risk of his army. He retired inland, again offered battle, was again defeated and forced back into Pennsylvania. So decided did the superiority of the British army prove to be that eventually Philadelphia itself, then the capital of the Confederacy, had to be abandoned.
Meanwhile another British army under the command of General Burgoyne held Canada. That province had shown no disposition to join in the revolt; an early attempt on the part of the rebels to invade it had been successfully repelled. Besides English and German troops, Burgoyne had the aid of several tribes of Indian auxiliaries, whose aid the British Government had been at some pains to secure—a policy denounced by Chatham in a powerful and much-quoted speech. Burgoyne was a clever and imaginative though not a successful soldier. He conceived and suggested to his Government a plan of campaign which was sound in strategic principle, which might well have succeeded, and which, if it had succeeded, would have dealt a heavy and perhaps a decisive blow to American hopes. How far its failure is to be attributed to his own faulty execution, how far to the blunders of the Home Government, and how far to accidents which the best general cannot always avoid, is still disputed. But that failure was certainly the turning-point of the war.
Burgoyne's project was this: He proposed to advance from Canada and push across the belt of high land which forms the northern portion of what is now New York State, until he struck the upper Hudson. Howe was at the same time to advance northward up the Hudson, join hands with him and cut the rebellion in two.
It was a good plan. The cutting off and crushing of one isolated district after another is just the fashion in which widespread insurrectionary movements have most generally been suppressed by military force. The Government accepted it, but, owing as it would seem to the laziness or levity of the English Minister involved, instructions never reached Howe until it was too late for him to give effective support to his colleague. All, however, might have prospered had Burgoyne been able to move more rapidly. His first stroke promised well. The important fort of Ticonderoga was surprised and easily captured, and the road was open for his soldiers into the highlands. But that advance proved disastrously slow. Weeks passed before he approached the Hudson. His supplies were running short, and when he reached Saratoga, instead of joining hands with Howe he found himself confronted by strongly posted American forces, greatly outnumbering his own ill-sustained and exhausted army. Seeing no sign of the relief which he had expected to the south—though as a fact Howe had by this time learnt of the expedition and was hastening to his assistance—on October 6, 1777, he and his army surrendered to the American commander, General Gates.
The effect of Burgoyne's surrender was great in America; to those whose hopes had been dashed by the disaster of Long Island, the surrender of New York and Washington's enforced retreat it brought not only a revival of hope but a definite confidence in ultimate success. But that effect was even greater in Europe. Its immediate fruit was Lord North's famous "olive branch" of 1778; the decision of the British Government to accept defeat on the original issue of the war, and to agree to a surrender of the claim to tax the colonists on condition of their return to their allegiance. Such a proposition made three years earlier would certainly have produced immediate peace. Perhaps it might have produced peace even as it was—though it is unlikely, for the declaration had filled men's souls with a new hunger for pure democracy—if the Americans had occupied the same isolated position which was theirs when the war began. But it was not in London alone that Saratoga had produced its effect. While it decided the wavering councils of the British Ministry in favour of concessions, it also decided the wavering councils of the French Crown in favour of intervention.
As early as 1776 a mission had been sent to Versailles to solicit on behalf of the colonists the aid of France. Its principal member was Benjamin Franklin, the one revolutionary leader of the first rank who came from the Northern colonies. He had all the shrewdness and humour of the Yankee with an enlarged intelligence and a wide knowledge of men which made him an almost ideal negotiator in such a cause. Yet for some time his mission hung fire. France had not forgotten her expulsion from the North American continent twenty years before. She could not but desire the success of the colonists and the weakening or dismemberment of the British Empire. Moreover, French public opinion—and its power under the Monarchy, though insufficient, was far greater than is now generally understood—full of the new ideals which were to produce the Revolution, was warmly in sympathy with the rebellion. But, on the other hand, an open breach with England involved serious risks. France was only just recovering from the effects of a great war in which she had on the whole been worsted, and very decidedly worsted, in the colonial field. The revolt of the English colonies might seem a tempting opportunity for revenge; but suppose that the colonial resistance collapsed before effective aid could arrive? Suppose the colonists merely used the threat of French intervention to extort terms from England and then made common cause against the foreigner? These obvious considerations made the French statesmen hesitate. Aid was indeed given to the colonial rebels, especially in the very valuable form of arms and munitions, but it was given secretly and unofficially, with the satirist Beaumarchais, clever, daring, unscrupulous and ready to push his damaged fortunes in any fashion, as unaccredited go-between. But in the matter of open alliance with the rebels against the British Government France temporized, nor could the utmost efforts of Franklin and his colleagues extort a decision.
Saratoga extorted it. On the one hand it removed a principal cause of hesitation. After such a success it was unlikely that the colonists would tamely surrender. On the other it made it necessary to take immediate action. Lord North's attitude showed clearly that the British Government was ready to make terms with the colonists. It was clearly in the interests of France that those terms should be refused. She must venture something to make sure of such a refusal. With little hesitation the advisers of the French Crown determined to take the plunge. They acknowledged the revolted colonies as independent States, and entered into a defensive alliance with these States against Great Britain. That recognition and alliance immediately determined the issue of the war. What would have happened if it had been withheld cannot be certainly determined. It seems not unlikely that the war would have ended as the South African War ended, in large surrenders of the substance of Imperial power in return for a theoretic acknowledgment of its authority. But all this is speculative. The practical fact is that England found herself, in the middle of a laborious, and so far on the whole unsuccessful, effort to crush the rebellion of her colonies, confronted by a war with France, which, through the close alliance then existing between the two Bourbon monarchies, soon became a war with both France and Spain. This change converted the task of subjugation from a difficult but practicable one, given sufficient time and determination, to one fundamentally impossible.
Yet, so far as the actual military situation was concerned, there were no darker days for the Americans than those which intervened between the promise of French help and its fulfilment. Lord Cornwallis had appeared in the South and had taken possession of Charleston, the chief port of South Carolina. In that State the inhabitants were less unanimous than elsewhere. The "Tories," as the local adherents of the English Crown were called, had already attempted a rebellion against the rebellion, but had been forced to yield to the Republican majority backed by the army of Washington. The presence of Cornwallis revived their courage. They boasted in Tarleton, able, enterprising and imperious, an excellent commander for the direction of irregular warfare, whose name and that of the squadron of horse which he raised and organized became to the rebels what the names of Claverhouse and his dragoons were to the Covenanters. Cornwallis and Tarleton between them completely reduced the Carolinas, save for the strip of mountainous country to the north, wherein many of those families that Tarleton had "burnt out" found refuge, and proceeded to overrun Georgia. Only two successes encouraged the rebels. At the Battle of the Cowpens Tarleton having, with the recklessness which was the defeat of his qualities as a leader, advanced too far into the hostile country, was met and completely defeated by Washington.