January 3, 1777 – A second victory for Washington as his troops defeat the British at Princeton and drive them back toward New Brunswick. Washington then establishes winter quarters at Morristown, New Jersey. During the harsh winter, Washington's army shrinks to about a thousand men as enlistments expire and deserters flee the hardships. By spring, with the arrival of recruits, Washington will have 9,000 men.
March 12, 1777 – The Continental Congress returns to Philadelphia from Baltimore after Washington's successes against the British in New Jersey.
April 27, 1777 – American troops under Benedict Arnold defeat the British at Ridgefield, Connecticut.
June 14, 1777 – The flag of the United States consisting of 13 stars and 13 white and red stripes is mandated by Congress; John Paul Jones is chosen by Congress to captain the 18 gun vessel Ranger with his mission to raid coastal towns of England.
June 17, 1777 – A British force of 7700 men under Gen. John Burgoyne invades from Canada, sailing down Lake Champlain toward Albany, planning to link up with Gen. Howe who will come north from New York City, thus cutting off New England from the rest of the colonies.
July 6, 1777 – Gen. Burgoyne's troops stun the Americans with the capture of Fort Ticonderoga on Lake Champlain. Its military supplies are greatly needed by Washington's forces. The loss of the fort is a tremendous blow to American morale.
July 23, 1777 – British Gen. Howe, with 15,000 men, sets sail from New York for Chesapeake Bay to capture Philadelphia, instead of sailing north to meet up with Gen. Burgoyne.
July 27, 1777 – Marquis de Lafayette, a 19 year old French aristocrat, arrives in Philadelphia and volunteers to serve without pay. Congress appoints him as a major general in the Continental Army. Lafayette will become one of Gen. Washington's most trusted aides.
August 1, 1777 – Gen. Burgoyne reaches the Hudson after a grueling month spent crossing 23 miles of wilderness separating the southern tip of Lake Champlain from the northern tip of the Hudson River.
August 16, 1777 – In the Battle of Bennington, militiamen from Vermont, aided by Massachusetts troops, wipe out a detachment of 800 German Hessians sent by Gen. Burgoyne to seize horses.
August 25, 1777 – British Gen. Howe disembarks at Chesapeake Bay with his troops.
September 9-11, 1777 – In the Battle of Brandywine Creek, Gen. Washington and the main American Army of 10,500 men are driven back toward Philadelphia by Gen. Howe's British troops. Both sides suffer heavy losses. Congress then leaves Philadelphia and resettles in Lancaster, Pennsylvania.
September 26, 1777 – British forces under Gen. Howe occupy Philadelphia. Congress then relocates to York, Pennsylvania.
October 7, 1777 – The Battle of Saratoga results in the first major American victory of the Revolutionary War as Gen. Horatio Gates and Gen. Benedict Arnold defeat Gen. Burgoyne, inflicting 600 British casualties. American losses are only 150.
October 17, 1777 – Gen. Burgoyne and his entire army of 5700 men surrender to the Americans led by Gen. Gates. The British are then marched to Boston, placed on ships and sent back to England after swearing not serve again in the war against America. News of the American victory at Saratoga soon travels to Europe and boosts support of the American cause. In Paris the victory is celebrated as if it had been a French victory. Ben Franklin is received by the French Royal Court. France then recognizes the independence of America.
November 15, 1777 – Congress adopts the Articles of Confederation as the government of the new United States of America, pending ratification by the individual states. Under the Articles, Congress is the sole authority of the new national government.
December 17, 1777 – At Valley Forge in Pennsylvania, the Continental Army led by Washington sets up winter quarters.