 Complete the following phrase:  Lee then moved onto the offensive, conducting a series of battles that lasted seven days June 25  July 1 and pushed McClellan back to a safe but nonthreatening position on the James River. McClellan actually struck first on June 25 at the Battle of Oak Grove, during which two Union divisions attempted to seize ground on which McClellan planned to build siege batteries. McClellan planned to attack again the next day but was distracted by the Confederate attack at 