Atlanta (CNN) "The Battle of Atlanta," one of the world's largest paintings, settled into its new home Friday night after two days of moving that followed months of preparation.

Crews lowered the cyclorama painting -- which is in two pieces, rolled onto 45-foot-tall spools -- through the roof of the Atlanta History Center in the city's Buckhead neighborhood.

The successful relocation of the massive painting was an engineering feat, given its age (131 years), weight (between 4 and 5 tons) and fragile condition.

The depiction of the momentous Civil War battle was housed for nearly 100 years in a leaky building at Atlanta's Grant Park.

The "Battle of Atlanta" was created by German artists during the heyday of paintings called cycloramas, and only a few still exist in North America.

Plans call for the work to be carefully restored in a new wing under construction at the Atlanta History Center.

The first spool was removed late Thursday from the shuttered Atlanta Cyclorama & Civil War Museum by cranes and trucked about 12 miles north to the center. The second spool was taken out Friday morning.

Both were lifted by crane over a few hours Friday and set into their new home.

"All indications point to everything being successful," Jackson McQuigg, vice president of properties for the history center, said Saturday. "We will know for sure when the painting is unscrolled. There's a heck of a lot of work to be done on the painting."

"The Battle of Atlanta" -- which, if stretched out, is longer than a football field -- may not be unfurled for several weeks, officials said.

While the artwork is irreplaceable, the history center has insured it for $7.5 million.

Throughout the move's preparation and execution, officials emphasized the need to be methodical and slow. Wind and problems attaching a base plate to one spool caused some delays.

McQuigg described the experience as "frustrating, frightening, prideful and exhilarating."

Promoting dialogue about crucial part of US history

Sheffield Hale, the Atlanta History Center's president and chief executive, called the first day of the move "a red-letter day for history."

The center will tell stories related to the city-owned painting, explaining its connections to Atlanta's history and the civil rights movement.

Officials say the work previously was interpreted in many ways, from extolling the emergence of the "New South" after the Civil War to the "Lost Cause" narrative, which proclaimed the conflict was more about states' rights than slavery.

Hale said the history center emphasizes the war was indeed about slavery, and it's known that slaves built much of Atlanta's defenses during the war. But, he added, the center welcomes respectful dialogue about root causes.

The 360-degree renderings of landscapes, city skylines and war were popular before movies came on the scene.

Hale said the "wow factor" will return to the painting. And it has to be seen in person to be truly appreciated, he said. "It's real, something they can't see at home or on a (computer) screen."

A spool holding one half of the painting prepares to leave Atlanta's Grant Park on Friday.

The painting, which depicts the July 1864 Battle of Atlanta, was to be a tribute to the Northern victory, but, perhaps ironically, it ended up in the South.

The focal point of the sprawling painting is fierce fighting around a house, with Confederates firing from behind cotton bales. Federal troops and cavalry are rushing toward that point and are on the cusp of victory.

The fall of Atlanta more than a month later helped to re-elect President Abraham Lincoln.

The painting is put in a horizontal position so it can be placed on a truck bed.

Painting was presented in leaky building

Over more than a century at Grant Park, the painting began to show its age. Observers worried the old building was contributing to the painting's slow deterioration. A recent visit to the brick-walled, circular room showed some water seepage on the floor.

Assistant conservators Chris Szaro, Danielle Collier and Megan Crouch.

Among those witnessing preparations for this week's move were three Weilhammer & Schoeller painting assistant conservators who have worked on the piece since last summer.

Chris Szaro said a double fiberglass backing has ensured the survival of the painting, which he said is brittle in places. The trio said they had to place buckets at the Grant Park building to capture water that dripped during rainfall. The bottom of the painting will need particular attention, they said.

All three said they appreciate the craftsmanship of the artists behind "The Battle of Atlanta." They point out exquisite details -- such as faces of soldiers, or mountains and the city skyline.

"It's the sense of drama and movement," Megan Crouch said. "The scale is most impressive."

The painting, made of Belgian linen, will be thoroughly restored before an autumn 2018 opening.

McQuigg said the artwork will be cleaned and varnish removed "because (the painting) has yellowed over the years."

Conservators will have to make decisions on treatments and a new varnish.

"We don't want to make the painting look brand new," McQuigg said. "We want to preserve the stain of time, so there is a lot more preservation and conservation going on, rather than restoration."

The painting, with an accompanying diorama, shows the Battle of Atlanta on July 22, 1864.

Trying to immerse viewers in the scene

Officials said the painting will be presented in the way its creators originally intended. That's partially because parts of the painting were cut over the years.

In 1921, the installation crew at Grant Park had a bit of a problem -- the painting was too big for the building. The solution? Lop off a 6-foot-wide section of the battle scene (fortunately, near an entrance tunnel).

"The Battle of Atlanta" also lost nearly 8 feet of sky over the years as workers installed it in different buildings.

Conservators will repaint those missing pieces, working from old black-and-white photos of the 6-foot-wide section.

Exquisite details from the 19th-century cyclorama painting unfold during the scrolling process.

The painting also will have the proper perspective: The work hung like a shower curtain, and there were folds and creases.

And the painting will be displayed in its original hyperbolic, or hourglass shape. Through proper tension at the top and bottom, its horizon will appear closer to the viewer, restoring the original 3-D illusion.