When the Union charge commenced, the 10th Missouri Cavalry, USA, started forward with a yell and bugles blaring, but halfway down the slope the men hesitated and stopped when the Confederates showed no sign of breaking. Union Lieutenant Colonel Frederick W. Benteen, later of Little Big Horn fame, rode out front, shouting and waving his sword for his men to continue, but they stood frozen in their tracks, intimidated by a force three times their size. As the 10th Missouri faltered, troops behind still charged forward. To prevent a collision and continue the attack, the 4th Iowa Cavalry, USA, pushed through the stalled lines of the 10th Missouri and resumed the charge. All along the Union line, in a chain reaction from left to right, the charge was renewed, and the Confederate line soon collapsed.