General Sullivan, at his base in Hanover, New Jersey, ordered his commanders on August 20 to prepare their troops for a march the next day. Sources do not describe the precise composition of the troops chosen, but most of them were drawn from Sullivan's division, which consisted of the First and Second Maryland Brigades. These brigades comprised the regiments of the Maryland Line; additional troops chosen for the operation included companies from the 2nd Canadian Regiment and a company of New Jersey militia. On the afternoon of August 21 two columns numbering about 1,000 in all left the camp. One column was led by Brigadier General William Smallwood, and the other, headed by Sullivan, consisted of troops led by a French officer who had been given a Continental Army brigadier's commission, the Chevalier Philippe Hubert Preudhomme de Borre. After reaching Elizabethtown late that evening, they rested for a few hours, and began crossing early the next morning. One detachment, led by Colonel Matthias Ogden, crossed opposite Fresh Kills and rowed partway up the kill, in order to approach their target, the militia brigade of Elisha Lawrence, from its rear. The remaining troops crossed near Palmer's run on the north side of the island, where they split into three groups. Smallwood and Sullivan led most of their columns away to attack specific targets, each leaving a regiment behind to cover their line of retreat.