On this day in history, June 18, 1778, Americans retake Philadelphia after the British army evacuates the city. Philadelphia was captured in September of 1777 by British General William Howe who was hoping to end the American rebellion by cutting off its head in Philadelphia. The Continental Congress, however, fled the city to York, Pennsylvania and continued to lead the rebellion from there.
After a massive British sea landing southwest of the city, George Washington and the Continental Army suffered thousands of casualties at the Battles of Brandywine and Germantown trying to save Philadelphia from capture, but to no avail. Thousands of patriots fled and nearly 20,000 British soldiers occupied the city.
General Howe, known for extreme caution, decided to wait out the winter in Philadelphia instead of attacking Washington's army to the north of the city. The occupation was devastating for Philadelphia. Homes and businesses were ransacked or destroyed. Supplies of all kinds were in short supply. Piles of the dead lay around the city. Meanwhile, the top officers lived in luxury in the confiscated homes of patriots who had fled.
The Continental Army passed the winter at Valley Forge, starving and freezing in makeshift huts. The one advantage they had was that this hastily prepared army finally had some time to train. Washington and the newly arrived Prussian Baron, Friedrich Wilhelm von Steuben, instituted a strict regimen of firing and marching exercises that better enabled the army to fight against the British once the campaigns began again in 1778.
In October of 1777, the army of British Major General John Burgoyne was forced to surrender to American General Horatio Gates at Saratoga, New York. This surrender encouraged France to join the Americans by declaring war against Great Britain the following February, forcing Britain to redesign its entire war strategy. Large numbers of troops were sent from North America to the West Indies to defend British interests there. General Howe was replaced by General Sir Henry Clinton, who was ordered to abandon Philadelphia and return to New York as both cities were now endangered by blockade of the French fleet.
When Clinton took over from Howe in May, he immediately began planning the evacuation of the city. He did not, however, have enough ships to transport thousands of troops, horses, supplies and numerous Loyalists and their belongings who wanted to flee as well. Consequently, he ordered an overland march of the troops and allowed thousands of Loyalists to flee to New York on his ships.
The city was finally abandoned on June 18 and George Washington sent Major General Benedict Arnold, who had not yet committed his act of treason, into the city to become its temporary military commander. Congress returned shortly after. The Continental Army, meanwhile, came out of Valley Forge and chased Clinton's army on its way back to New York, culminating in the massive Battle of Monmouth, a battle involving 25,000 men. The battle was essentially a draw, ending up with the British back in New York City and the Continental Army back at White Plains, New York, the exact positions they were in two years earlier before the New Jersey and Philadelphia campaigns.