In 1925 in Alaska, diphtheria was spreading quickly.
The terrible disease was infecting the children in the coastal town of Nome, causing high fevers and breathing problems.
Some were dying. All were at risk.
The town did not have enough serum to stop the disease.
At this time, serum was used to protect people everywhere from infectious diseases.
But only the city of Anchorage had enough of the diphtheria serum to help Nome.
Unfortunately, Anchorage was eight hundred miles away, and a huge snowstorm was keeping airplanes on the ground.
There was only one way to get the serum to Nome—by dogsled.
A call went out for dog teams to help in the effort.
Twenty of the best dogsled drivers, called mushers, and about one hundred and fifty of the fastest dogs were chosen.
They were formed into relay teams.
Each team would travel from one roadhouse to another along the trail.
Roadhouses were places that mailmen used to deliver mail to isolated areas of Alaska.
At each roadhouse, one team would pass the serum to another team.
This would allow the serum, packed in a cylinder to protect it from the cold, to go from team to team until it reached Nome.
The effort was called the "Great Race of Mercy," and later would be known as the "Serum Run of 1925."
The serum would be taken by train from Anchorage to the town of Nenana, and then the mushers would take over to get it to Nome.
The mushers would have to cover 674 miles!
When Gunnar Kasson's team was called, he knew his lead dog would be Balto.
Of the 13 dogs on his team, Balto, a Siberian husky, was very special.
He looked like a wolf, but he was gentle and could follow any trail.
The big, black dog could think for himself.
Kasson was to make the run along the coast of the Seward Peninsula from the town of Bluff to Point Safety, a distance of about forty miles.
Then, another team would take the serum the remaining 22 miles from Point Safety into Nome.
But the team Kasson was waiting for was late getting to Bluff, because the storm had gotten worse.
The temperature was thirty degrees below zero.
The tired and cold driver warned Kasson it was too dangerous to continue, so Kasson tried to wait out the storm.
But when Kasson saw that the storm wasn't letting up, he decided to go anyway.
People were dying and he had to get the serum to Nome.
Wind conditions were dangerous.
The snow kept falling hard, and the trail was almost impossible to follow.
Sometimes the snow was up to Kasson's chest, and he would push the sled forward to help his dogs.
As temperatures dropped, the ice became sharp and cut the dogs' feet.
The sled kept turning over too.
One time, the serum cylinder was lost in the snow.
Kasson's fingers were badly frozen trying to find it with his bare hands.
The dogs got tangled up in the harness and fought with each other, but Balto remained calm.
When the other dogs wanted to stop, Balto wouldn't let them.
The storm got steadily worse. The winds reached eighty miles per hour.
Kasson could not see the dogs in front of him, or even his own hand in front of his face because of the driving snow.
He had to leave everything up to Balto.
Kasson trusted that Balto would get them to their final destination—Point Safety.
Meanwhile, a telegraph message was sent to the roadhouse in the town of Solomon where Kasson was supposed to stop for a short while.
The message said that Kasson should stay in Solomon, and that he should not try for Point Safety yet.
The weather was just too dangerous.
Lost in the blizzard, Kasson passed right by Solomon and never got the message!
When Kasson and Balto reached Point Safety that night, the other relay team was sleeping.
The team at Point Safety had thought Kasson had stayed in Solomon.
The time it would take for the new team to get hitched up to make the last run would cause too much of a delay.
So, with great sadness, Kasson looked into Balto's eyes.
Many dogs had died during this serum run, and Balto surely needed rest.
But Kasson and Balto would continue on to Nome—22 miles away.
At 5:30 a.m., February 2, 1925, after 20 hours and about 62 miles on the trail, Balto and Kasson made it to Nome.
All the brave teams had covered 674 miles in less than five days.
Kasson fell on his knees and hugged Balto.
Tears came to his eyes as he tried to remove the ice cutting into his dog's paws.
News spread all over the world about the heroic dog that saved Nome's children.
Today, a bronze statue of Balto stands in New York City's Central Park in his honor.