army is approaching. Buford recognizes that, with precedent from previous battles, the Confederates will arrive at Gettysburg first and entrench in strong positions, forcing the Union to charge them and suffer heavy casualties. To prevent this, he opts to stand and fight where he is, judging the terrain to be "lovely ground" for slowing the Confederate advance. Buford sends word to I Corps commander Maj. Gen. John F. Reynolds to bring up reinforcements. Heth's troops engage Buford's cavalry the following morning, July 1, with Richard S. Ewell's Second Corps moving in to flank them. Reynolds brings his corps forward, but is killed by a Confederate sharpshooter. The Union army is pushed out of Gettysburg to Cemetery Ridge, and Lee—rejecting Longstreet's suggestion to redeploy south of Gettysburg and go on the defensive—orders Ewell to take the Union position "if practicable". However, Ewell hesitates and does not engage. The armies concentrate at their chosen positions for the remainder of the first day. At Confederate headquarters at Seminary Ridge, Maj. Gen. Isaac R. Trimble angrily denounces Ewell's inaction to Lee, and requests another assignment. On the second day, July 2, Col. Strong Vincent's brigade from the Union V Corps is deployed to Little Round Top, and Vincent places the 20th Maine at the end of the line, warning Chamberlain that he and his regiment are the flank, and that if they retreat, the Confederate army can swing around behind them and rout the Union forces. Lee orders Longstreet to deploy his two available divisions to take Little Round Top and the neighboring Big Round Top. As Longstreet's corps deploys, Maj. Gen. John Bell Hood, commanding one of the divisions, protests to Longstreet; with the Union holding the high ground, he would lose half his forces if he attacked as ordered. Longstreet, despite his own protests to Lee, orders Hood to attack; Hood is later wounded fighting at Devil's Den. At the summit of Little Round Top, Chamberlain and the 20th Maine fight off wave after wave of advancing Confederates, and begin running out of ammunition. Colonel Vincent is mortally wounded, and none of the other three regiments in his brigade are able to provide support. Chamberlain orders his men to fix bayonets, and charge in a right wheel down the slope against the attacking Confederates, which Chamberlain describes as "we'll swing it down; we swing like a door." The attack successfully drives the