Uncertain whether Baltimore or Washington was the Confederate objective, Wallace knew he had to delay their approach until reinforcements could reach either city. Wallace saw Monocacy Junction, also called Frederick Junction, southeast of Frederick, as the most logical point to defend Baltimore and Washington. A plain extended north and west from the river at Monocacy Junction to the Catoctin Mountains, away. From Monocacy Junction, the B&O Railroad's bridge crossed the river at the foot of a bluff. A wooden bridge provided the Georgetown Pike access to Washington across the Monocacy River, a short distance downriver, while a stone bridge took Baltimore Pike across the Monocacy upriver. Two blockhouses, one near the junction and another on the bluff above the railroad bridge, provided additional protection. A 24-pound howitzer was installed at the blockhouse on the bluff. If Wallace could stretch his force across of the stream to protect both turnpike bridges, the railroad bridge, and several river fords, he could force Early to disclose the strength and objective of the Confederate force and delay him as long as possible.