I.at the end of the volume.] [Sidenote: May 1.] Not long after this incursion into Jersey, an enterprise was undertaken against General Lacy, who, with a small number of Pennsylvania militia, seldom amounting to six hundred, and sometimes not exceeding fifty, watched the roads leading to Philadelphia on the north side of the Schuylkill, and was generally posted within twenty miles of that town.
[Sidenote: General Lacy surprised.] This expedition was entrusted to Colonel Abercrombie and Major Simcoe, who avoided all the posts Lacy had established for his security, and threw a body of troops into his rear before he discovered their approach.

After a short resistance, he escaped with the loss of a few men killed, and all his baggage.

His corps were entirely dispersed, and he was soon afterwards relieved by General Potter.
To maintain the command of the water as far as was practicable, congress had ordered impediments to be sunk in many of the rivers of common use, so as to obstruct the passage up them, and had constructed frigates, and other smaller vessels, to be employed above those impediments or elsewhere, as the occasion might require.

Several of them had been commenced above Philadelphia, but were not completed when the British obtained the command of the river.

General Washington then became apprehensive for their safety, and repeatedly expressed his desire that they should be sunk in such a manner as to be weighed with difficulty, should any attempt be made to raise them.