AUGUSTA – A Maine State Museum initiative to preserve and photograph the state’s collection of more than 300 historic flags and banners is nearly complete and coming to an end.

The program, which kicked off in 1992, has used $470,000 in private, state and federal money to clean and store the flags. The flags are now resting flat on aluminum trays in covered storage cabinets at the museum’s annex in Hallowell.

The job will be finished in five or six weeks, when all but the most decrepit flags will have been cleaned and mounted.

Thirty of the flags came from display cases in the Hall of Flags at the State House, where they were exposed to excessive light, the pull of gravity and damaging fluctuations in temperature and humidity.

The State House flags were removed four years ago, replaced by two dozen replicas that are more colorful and less fragile than the originals. Other flags in the state’s collection had been folded and stored in boxes for decades until they were cleaned and mounted as part of the flag preservation effort.

Earle Shettleworth Jr., the state historian, said if the flags at the State House had remained in their glass-fronted metal cases much longer, “soon we’d have a pile of dust” instead of a collection of flags.

The state’s historic flags and banners, many of which are made of silk, date from the early 19th century through the late 20th century. Many are military flags, including large battle flags and parade flags. Others promote various causes such as the temperance movement.

And still others have stories to tell.

The collection includes two small fragments of a flag that the 16th Maine Regiment carried on the first day of the Battle of Gettysburg in 1863. Facing capture, the men of the 16th Maine cut two flags into pieces that day and hid the fragments in their clothing or belongings to keep them out of Confederate hands.

Of more recent vintage is a fragment of a flag from the USS Newcomb, a World War II destroyer. After the Newcomb helped sink the Japanese battleship Yamashiro in 1943, the ensign that had flown aboard the Newcomb was cut up and the pieces distributed to the crew as mementos, according to the state museum. It acquired its fragment from the late Foster Sewall Ellis of Brooklin, who served aboard the Newcomb.

“I’ve definitely learned the power of an artifact, the power of an object to bring the past to the present,” said Laurie LaBar, curator of historic collections at the state museum.

“At a certain point,” she said of the 16th Maine fragments and the men who hid them at Gettysburg, “these guys stopped working on their own personal safety to save this flag.”