JEFFERSON CITY - It's a school day, but Joe Campbell isn't in class.
The St. James High School biology teacher has traded in his microscopes and slides for combat boots and fatigues.
Capt. Campbell has been called up to command the first unit of a Missouri National Guard unit to be deployed since the war in Iraq began.
As Campbell prepared to lead 158 men and women -- possibly to battle -- he reflected on his new full-time job.
"There is fear," Campbell said. "Fear of really taking care of my troops and making sure we come back safe."
The soldier also leaves behind a wife and three children ages 7, 5 and 3 -- not to mention dozens of students.
"That's the hardest thing," he said.
A week ago, Campbell had his last day in the classroom. He told his students he would be leaving and answered their questions.
"They asked me, 'how long?' and I said, maybe next year I'll be back, maybe three months, I don't know," he said.
At a deployment ceremony Thursday at the state's National Guard headquarters in Jefferson City, members of the 1221st Transportation Division said their goodbyes to family, friends and sweethearts.
From there, no one knows where they are going or how long they will be gone.
At the ceremony, Holden praised the troops.
"I hope all of you in the unit know how proud we are that you're fighting on behalf of us," Holden said. "We only ask two things of you: come home safe and come home quickly."
The 1221st unit is part of the largest Missouri National Guard callup since World War II, said the guard's chief spokesman, Bill Ratliff. More than 2,000 of the state's National Guard Troops have been called to active duty.
This isn't the first time the 1221st has been called to serve. The unit, which specializes in transporting materials to troops in the field, served in the 1991 Gulf War. The unit also helped out in the Great Flood of 1993.
The soldiers come from four Mid-Missouri cities: Dexter, Trenton, Centertown and Jefferson City.
As the Jefferson High School marching band played "God Bless America," the troops looked out over an audience of tearful loved ones waving American flags. Once the 45-minute ceremony ended, the troops gave loved ones one last hug and then boarded a bus.
Just before Campbell left, he recalled how tons of students had given him cards and wished him good luck.
"It made me proud to be a teacher."