The Confederate plan did not call for an attack against the Union position along Beaver Dam Creek, but a series of maneuvers was intended to make the defenses there untenable. Poor communication and unexpected obstacles caused delays, and Lee felt vulnerable because a large portion of his army lay isolated on the other side of the Chickahominy. He decided to test the Union defenses there while his primary plan unfolded. Southern infantrymen suddenly advanced from the village of Mechanicsville across nearly one mile of shell-swept ground. Most of the regiments had seen little if any combat, and their inexperience quickly became apparent. Some units advanced too far, while others stubbornly held their ground along the creek bottom long after they should have fallen back. None advanced beyond the creek. The first battle of the most critical campaign in the Confederacy’s short history ended disastrously.