General Washington kept the American army in the mountain fastnesses, where he could not be attacked, except under great disadvantages, and the English general resolved on an expedition against Philadelphia.
Embarking on board the fleet, the regiment sailed for Chesapeak-bay, and from thence up the Elk River, to Elk Ferry, where it landed about the end of August: the fifth, Tenth, twenty-seventh, fortieth, and fifty-fifth regiments, formed the second brigade under Major-General Grant.
The American army took up a position at Brandywine Creek, to oppose the advance of the British on Philadelphia, and on the 11th of September the enemy's posts were attacked; the Tenth forming part of the force selected to attack the American troops posted at Chad's Ford. After a sharp cannonade, the troops rushed through the stream with fixed bayonets, the fourth foot taking the lead, and, overpowering all resistance, captured three brass field-pieces and a howitzer. The Americans were routed at all points, and they made a precipitate retreat. The Tenth had two rank and file killed, and six wounded, on this occasion.
The regiment passed the night on the field of battle, and marched on the following day to Concord; on the 13th of September it arrived at Ashtown, and on the 25th the troops pitched their tents at Germantown, about six miles from Philadelphia, which city was taken possession of by the grenadiers.
On the 29th of September, the Tenth and forty-second regiments were detached from the camp at Germantown, under the orders of Lieut.-Colonel Stirling, of the forty-second, to attack a strong redoubt erected by the Americans on the Jersey shore, at a place called Billing's-point, to prevent the removal of a sunken barrier across the river Delaware. The two regiments crossed the river from Chester on the 1st of October, and on approaching the redoubt, three hundred Americans in garrison fled; having first set fire to their barracks and spiked their cannon. The Tenth and forty-second pursued the Americans about two miles, but were unable to overtake them.
Billing's-point redoubt being thus captured, the obstructions to the navigation of the Delaware at that point were removed, and the Tenth and forty-second crossed the river to Chester, where they were joined by the twenty-third, and the three regiments escorted a large convoy of provisions to the camp at Germantown.
The British general having sent off several detachments, the Americans resolved to hazard another battle, and they attacked the position at Germantown at daybreak on the morning of the 4th of October; but were repulsed. The light company of the Tenth signalized itself on this occasion and had several men killed and wounded: the battalion companies of the regiment had their post on the right of the village, but they were not engaged.
In the middle of October, the army removed to the immediate vicinity of Philadelphia, and two forts on the river were reduced. In the early part of December, the British advanced towards the enemy's fortified camp at Whitemarsh; the Tenth took part in several movements and skirmishes, designed to bring on a general engagement, but the Americans kept close behind their entrenchments and abatis-de-bois, and the British returned to Philadelphia.
1778
The Tenth regiment passed the winter in comfortable quarters in the city of Philadelphia; but before the season for opening the campaign of 1778 arrived, the King of France concluded a treaty with, and agreed to aid, the Americans, which so completely changed the nature of the war, that it was deemed necessary to concentrate the army at New York.