MARIETTA - Twenty-eight new graduates of the Georgia Military Institute became second lieutenants Saturday afternoon in a historic ceremony on the original grounds of the school.

The GMI had been headquartered in Macon until 2008. Saturday's event marked its symbolic return to its new home of Marietta, where it was founded in 1851, several years before the Civil War. The 28 GMI graduates were commissioned as second lieutenants in the Georgia Army National Guard, of which GMI serves as an officer candidate school.

The event took place on the lawn of the Atlanta Hilton/Marietta Conference Center off Powder Spring Street, the site of the original location of GMI.

As part of the graduation ceremony, the 28 officer candidates were "pinned" as second lieutenants by friends and family members.

"You've earned it," Maj. Gen. William T. Nesbitt, adjutant general of Georgia, told the graduates. "You certainly are embarking on a great change in your career, beginning your careers as officers."

For at least a year, the soldiers learned how to be officers in the Georgia Army National Guard. A typical training weekend for them included preparing equipment for field maneuvers, academic instruction on the science and tactics of military operations, followed by intense physical training.

The graduates were from around the state.

"The most difficult part of it was just staying motivated for the whole 18-month program and sticking it out," said Tiffany Bellinger, 29, of Decatur, who graduated Saturday. She said she has been assigned to the 165th Quartermaster Air Direct Support at Dobbins Air Reserve Base in Marietta.

After they were pinned, the newly commissioned officers took an oath of duty. Awards were then presented to top graduates for academic and leadership achievements.

"Once you finish your platoon and command time, you need to give back to this program," said Capt. Calvin Oxendine, a GMI instructor. "That's what this is all about, strengthening and maintaining the Georgia Army National Guard."

The class of 2009 was the 48th GMI graduation class and the first in decades to graduate in Marietta.

GMI was established in Marietta in 1851 on Powder Springs Street, at the site of the present conference center. It was chartered as the state's first military institute.

During the Civil War, Union Gen. William Tecumseh Sherman and his troops burned 13 of the institute's 14 buildings during his March to the Sea. GMI cadets left Marietta in 1864 to assist in the defense of Atlanta. The school never reopened. The original 110-acre campus included an academic building, barracks and a parade ground.

Brumby Hall is the only remaining structure of GMI. It was built in 1851 for Col. Arnoldus Brumby, the first superintendent of GMI, and his family. He directed the institute from 1851-59.

On Saturday, the conference center displayed one of four original cannons given by the federal government to GMI in 1851. It was captured by the Union in the Civil War and returned to Marietta in 1928.

In 1961, a state officer candidate school was established in Forsyth. It moved to Milledgeville in 1969 and then to Macon in 1986. The Georgia Army National Guard later renamed the school in honor of the original GMI.

In 2005, Naval Air Station in Marietta was included on the federal Base Realignment and Closure list, and the National Guard saw an opportunity to move its headquarters to the city.

The Georgia National Guard - which includes the Army National Guard, the Air National Guard and the Georgia State Defense Force - had been based on Confederate Avenue in Atlanta. It began relocating to NAS-Atlanta in September 2007, after the property was transferred from the Navy to the Army. As part of that move, GMI returned to Marietta in July 2008.