On May 31, Gen. Joseph E. Johnston attempted to overwhelm two Federal corps that appeared isolated south of the Chickahominy River. The Confederate assaults, though not well coordinated, succeeded in driving back the IV Corps and inflicting heavy casualties. Reinforcements arrived, and both sides fed more and more troops into the action. Supported by the III Corps and Sedgwick’s division of Sumner’s II Corps (that crossed the rain-swollen river on Grapevine Bridge), the Federal position was finally stabilized. Gen. Johnston was seriously wounded during the action, and command of the Confederate army devolved temporarily to Maj. Gen. G.W. Smith. On June 1, the Confederates renewed their assaults against the Federals who had brought up more reinforcements but made little headway. Both sides claimed victory. Confederate brigadier Robert H. Hatton was killed.