On June 12 Howe marched a significant force (more than 18,000 men) out of New Brunswick, through Bound Brook, and as far as Somerset, apparently in an attempt to draw Washington out of the hills. Washington, aware that Howe had left the army's heavy baggage behind, was not fooled and refused to move. Howe then abruptly retreated back to Piscataway on June 19, upon which Washington had some of his troops give chase, and he moved down out of the hills. A week later Howe tried to spring a trap on one of Washington's detachments that would have cut off the American retreat into the hills; this effort was repulsed in the Battle of Short Hills. After this failure, Howe embarked his army on transports and set sail for Chesapeake Bay, intending to take Philadelphia from the south.