CHARLESTON, S.C. - Researchers seem to have solved the mystery of what happened to the "Big Red" flag flown by Citadel cadets when they fired on a ship trying to resupply Fort Sumter three months before the Civil War.

The Post and Courier of Charleston reports a 10-by-7-foot flag with a large white Palmetto tree and a white crescent on a red field has been located in storage at an Iowa museum.

Researchers think it is the same flag that flew over Morris Island when cadets fired on the supply ship Star of the West, forcing the ship to turn away, in January of 1861.

The Civil War began that April with a Confederate bombardment of Union-held Sumter in Charleston Harbor.

The Citadel adopted a replica of the red flag as a spirit flag almost 20 years ago. But it was unclear what happened to the original.

A woman, who was not identified, posted information on the flag on the Internet two years ago. The Citadel Historical Council began researching and it led to the discovery of the flag at the State Historical Society of Iowa is Des Moines.

Council chairman Tex Curtis, a 1964 graduate of the state military college, calls the flag "a priceless historic artifact. It literally is The Citadel. It goes right to the beginning."

The school is discussing bringing the flag back to Charleston from the Iowa museum on a long-term loan.

Michael O. Smith, director of the Iowa museum, said the flag was donated by a Union Civil War veteran, Willard Baker, in 1919. Baker said he got the flag in Mobile, Ala.

Researchers think the flag was taken from Charleston to Mobile by Confederate Capt. James F. Culpepper, an 1854 Citadel graduate, and fell into Baker's hands when Union troops captured Fort Blakeley near Mobile in April 1865. Both Culpepper and Baker fought in that battle.

Smith said the flag has been in storage since 1919. He said officials knew it was from South Carolina because of the palmetto, the state symbol, but did not know the flag's significance.