don't jump. >> if buford does jump, he might survive the 50-foot fall. no one knows if he can swim. >> garrett said to me, the guy's going to knock himself out and he's going to fall. a minute later he said i might be going swimming today. >> and then nearly 25 minutes into the ordeal, matthew buford jumps. >> there he goes. >> oh! >> what y'all going to do? >> okay. he can swim. >> after he jumped into the river, he started treading water for a while. >> swim! >> and at this time, i'm thinking, okay, where's the rescue unit at? >> no matter what buford was thinking when he jumped, now in the water he seems to be fighting for his life and looks like a man who needs help. >> dude ain't doing good. >> dude ain't doing too good. >> authorities on the bridge toss down a lifeline, but it doesn't come close. you can see it off to the right. >> must have a hundred boats out there. >> by this time buford has been struggling for almost go minutes in the middle of a 500-foot-wide river. >> come on, man. >> matthew buford is losing strength. for the first time his

. >> the morning of july 1st, confederate infantry comes marching along, john buford's cavalry were spreadver the area. initial engagement occurs. >> reporter: day one ended with the north driven southward. historians debate whether richard ule could have destroyed them. day two, the you know staved off further loss of territory with ferocious fighting to the northeast. the epic siegedevil's den. >> day two is the bloodiest day of the battle. robert e. lee finds it is a different battle. >> reporter: day three, they penetrate the farthest into northern territory. but the union held at cemetery ridge, other scenes of unimaginable carnage, prompting george picket to leave 13,000 rebels on one final doomed thrust, the mile long assault known as picket's charge. >> those confederates that break position here, come through here, union reinforcements come on the scene, and confederates are driven away. >> reporter: nearly 18,000 killed, more wounded, captured, missing. the fighting continued another 21 months. the south would never again pose the same threat. that november lincoln would visit ge