In June 1777 British General John Burgoyne, known as "Gentleman Johnny" for his manners, moved south from the province of Quebec to gain control of the upper Hudson River valley. After his early capture of Fort Ticonderoga, his campaign had become bogged down in difficulties.[12] Elements of the army had reached the upper Hudson as early as the end of July, but logistical and supply difficulties delayed the main army at Fort Edward. One attempt to alleviate these difficulties failed when nearly 1,000 men were killed or captured at the August 16 Battle of Bennington.[13] Furthermore, news reached Burgoyne on August 28 that St. Leger's expedition down the Mohawk River valley had turned back after the failed Siege of Fort Stanwix.[14] Combined with earlier news that General William Howe had sailed his army from New York City on a campaign to capture Philadelphia instead of moving north to meet Burgoyne,[15] and the departure of most of his Indian support following the loss at Bennington, Burgoyne's situation was becoming difficult.[16] Faced with the need to reach defensible winter quarters, which would require either retreat back to Ticonderoga or advance to Albany, he decided on the latter. Consequent to this decision he made two further crucial decisions. He decided to deliberately cut communications to the north, so that he would not need to maintain a chain of heavily fortified outposts between his position and Ticonderoga, and he decided to cross the Hudson River while he was in a relatively strong position.[17] He therefore ordered Baron Riedesel, who commanded the rear of the army, to abandon outposts from Skenesboro south, and then had the army cross the Hudson just north of Saratoga between September 13 and 15.[18] American situation

General Horatio Gates, portrait by Gilbert Stuart
The Continental Army had been in a slow steady state of retreat ever since Burgoyne's capture of Ticonderoga early in July. By mid-August the army, then under the command of Major General Philip Schuyler, was encamped south of Stillwater, New York. On August 19, Major General Horatio Gates assumed command from Schuyler, whose political fortunes had fallen over the loss of Ticonderoga and the ensuing retreat.[19] Gates and Schuyler, who were from very different backgrounds, did not get along with each other, and had previously argued over command issues in the army's Northern Department.[20] Gates became the beneficiary of an army that was growing in size as a result of increased militia turnout following calls by state governors, the success at Bennington, and widespread outrage over the slaying of Jane McCrea, the fiancée of a Loyalist in Burgoyne's army, by Indians in Burgoyne's command.[21] Strategic decisions by the American commander in chief, Major General George Washington also improved the situation for Gates's army. Washington was most concerned about the movements of General Howe, and what his goal was. Aware that Burgoyne was also moving, he took some risks in July and sent aid north in the form of Major General Benedict Arnold, his most aggressive field commander, and Major General Benjamin Lincoln, a Massachusetts man noted for his influence with the New England militia.[22] In August, before he was certain that Howe had indeed sailed south, he ordered 750 men from Israel Putnam's forces defending the New York highlands to join Gates' army, and also sent some of the best forces from his own army: Colonel Daniel Morgan and the newly formed Provisional Rifle Corps, which comprised about 500 specially selected riflemen from Pennsylvania, Maryland, and Virginia, chosen for their sharpshooting ability.[23]

Map showing the movements of the opposing armies in the Saratoga campaign, and plan of the Battles of Saratoga (inset)
On September 7, Gates ordered his army to march north. A site known as Bemis Heights, just north of Stillwater and about 10 miles (16 km) south of Saratoga, was selected for its defensive potential, and the army spent about a week constructing defensive works designed by Polish engineer Thaddeus Kosciusko. The heights had a commanding view of the area and commanded the only road to Albany, where it passed through a defile between the heights and the Hudson. To the west of the heights lay more heavily forested bluffs that would present a significant challenge to any heavily equipped army.[24]
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