And most of the Americans were killed by the deadliest weapon in the enemy's arsenal: the roadside bomb, or IED, an improvised explosive device.
IEDs killed more than 40 American and coalition forces in October alone, up from five two years ago.
In response, the U.S. military has gone on the offensive.
Search and destroy missions are carried out across Afghanistan by a small army of elite units called "Task Force Paladin."
Only volunteers are allowed to serve on Paladin teams because the mission is so dangerous.
It was after midnight last month at Dover Air Force Base in Delaware. President Barack Obama went to the base as America's war dead came home.
Eight of the flag-covered caskets contained the remains of Americans who had been killed by roadside bombs in Afghanistan.
"It's been a terrorist tool of choice for many, many years," Col. Jeffrey Jarkowsky told 60 Minutes correspondent Byron Pitts.
Col. Jarkowsky was in charge of Task Force Paladin when we visited Afghanistan.
"'Look at us. We can kill, we can maim, we can destroy when we want to, and the Americans can't stop us,'" Pitts remarked.
"That's their intent, yes," Jarkowsky agreed.
The colonel says his squads are having more success finding those bombs. We spent two days on the road with Army Captain Dave Foster and his Paladin team. They were on patrol for less than an hour when they discovered their first bomb. It would not be the last.
"The IED that we found had a 107 millimeter rocket connected to a command wire. As the team was doing dismount and ops they found the command wire. A 107 millimeter rocket has approximately about eight pounds of explosives in the warhead," Capt. Foster explained.
They spotted it near a family's home. Staff Sergeant Max Cabrera found and then disconnected the command wire - or detonation wire - disabling the bomb.
Six Paladin soldiers have been killed in Afghanistan since 2008 on similar missions.
Despite the risk to himself, Staff Sgt. Cabrera picked up the bomb, and to avoid civilian casualties, he carried it behind an abandoned building and blew it up.
"You get scared, but when you got so many things going through your mind, you just don't even know what to concentrate on sometimes," Cabrera told Pitts.
Asked if he's scared, he said, "Yes sir. Everybody is. Lets you know you're still alive."
Cabrera is 26. His home is on the island of Saipan, in the West Pacific.
Asked what it takes to do the job of disabling bombs, Capt. Foster told Pitts, "A belief that you are making a difference and a little bit of craziness."
"A little bit of crazy goes a long way in Afghanistan," Pitts remarked.
"Yes sir. It does," Foster said.