The alliance with France put a new color upon every phase of the American contest. If, for instance, a French fleet should be already on its way across the Atlantic, and should enter Chesapeake Bay and threaten Philadelphia, the English would have to evacuate that city and retire to New York, risking the danger of being intercepted on the way by Washington's army. In view of such a possibility as this, the commander in chief of the American army held a council of war in which it was decided that they were not strong enough to risk a decisive engagement. It was, however, highly important that exact information should be gained as to the movements of the British around Philadelphia. In order that this might be accomplished, General Washington detached a group of soldiery from among the most able and valued of his army, and put them under Lafayette, with instructions to proceed into the country between the Delaware and Schuylkill, and there interrupt communications with Philadelphia, obstruct the incursions of the enemy's parties, and obtain intelligence of their motives and designs. Lafayette was overjoyed at being chosen for so important a charge; and on the 24th of May, 1778, he started out with about twenty-two hundred men. His force included the band of Iroquois warriors who had come from Albany to follow his fortunes, and who, because of their knowledge of forest-craft, were invaluable as scouts. The British could command about four times as many soldiers as had been assigned to Lafayette, but their intention was to keep the American force out of their way and, if possible, to avoid a direct encounter. For his camp Lafayette selected a piece of rising ground near the eleventh milestone north of Philadelphia, where there was a church, a grave-yard, and a few stone houses that might afford some protection in case of attack, and where four country roads led out to the four points of the compass. The place was called Barren Hill--name of ill-omen! But the fate of the day proved not altogether unfortunate for the young and intrepid commander. Naturally, the people in Philadelphia had heard of the approach of the young French noble whose fame had been ringing in their ears, and they prepared to go out and engage him--capture him, if possible. At that time they were indulging in a grand, week-long festival, with masquerades, dancing, and fireworks; and in anticipation of the quick capture of the young French hero, a special party was invited for the next evening at which the guests were promised the pleasure of meeting the distinguished prisoner.