Philadelphia campaign

The Philadelphia campaign (1777–1778) was a British military campaign during the American Revolutionary War designed to gain control of Philadelphia, the Revolutionary-era capital where the Second Continental Congress convened, formed the Continental Army, and appointed George Washington as its commander in 1775, and later authored and unanimously adopted the Declaration of Independence the following year, on July 4, 1776, which formalized and escalated the war.

In the Philadelphia campaign, British General William Howe failed to draw the Continental Army under George Washington into a battle in North Jersey. Howe then embarked his army on transports, and landed them at the northern end of the Chesapeake Bay, where they began advancing north toward Philadelphia. Washington prepared defenses against Howe's movements at Brandywine Creek, but was flanked and beaten back in the Battle of Brandywine on September 11, 1777. After further skirmishes and maneuvers, Howe entered and occupied Philadelphia. Washington then unsuccessfully attacked one of Howe's garrisons at Germantown prior to retreating to Valley Forge for the winter, where he and 12,000 faced the harshest winter of the war, including insufficient food and clothing.

Howe's campaign was controversial because, while he succeeded in capturing the revolutionary capital of Philadelphia, he proceeded slowly and did not aid the concurrent campaign of John Burgoyne further north, which ended in disaster for the British in the Battles of Saratoga and brought France into the war. Howe resigned during the occupation of Philadelphia and was replaced by his second-in-command, General Sir Henry Clinton.

In 1778, Clinton was ordered to evacuate Philadelphia and consolidate his troops in New York City, in anticipation of a combined Franco-American attack there. Many Loyalists also left Philadelphia, fearing persecution. Washington's forces shadowed the withdrawing British Army until they clashed at the Battle of Monmouth, one of the war's largest battles.

At the end of the Philadelphia campaign in 1778, the two armies found themselves in roughly the same strategic positions that they had been in before Howe launched the attack on Philadelphia.

Following William Howe's capture of New York City and George Washington's success in the Battles of Trenton and Princeton, the two armies settled into an uneasy stalemate in the winter months of early 1777. While punctuated by numerous skirmishes, the British Army continued to occupy outposts at New Brunswick and Perth Amboy in New Jersey.

In 1777, Howe proposed to George Germain, the British civilian official responsible for war's conduct, that British expedition be launched with the goal of capturing Philadelphia, the seat of the rebellious Second Continental Congress. Germain approved Howe's plan, although with fewer troops than Howe requested. He also approved plans by John Burgoyne for an expedition to "force his way to Albany" from Montreal. Germain's approval of Howe's expedition included the expectation that Howe would be able to assist Burgoyne, effecting a junction at Albany between the forces of Burgoyne and troops that Howe would send north from New York City.

Howe decided in early April 1777 against taking the British Army over land to Philadelphia through New Jersey since this route would entail having to cross of the broad Delaware River under hostile conditions and likely require the transportation or construction of necessary watercraft. Howe's plan, sent to Germain on April 2, isolated Burgoyne from any possibility of significant support, since Howe instead would take the British Army to Philadelphia by sea, and the New York garrison would be too small for any significant offensive operations up the Hudson River to assist Burgoyne.