ST. LOUIS – If you want to step back in time to the 1850s, you have to take some 19th-century stairs.

But now, you can simply take the elevator to get a view of history.

“This is the culmination of the CityArchRiver Project,” said Ryan McClure, Gateway Arch Park Foundation executive director. “It’s a $380-million project that is the largest public-private partnership in the history of the national park service.”

On Wednesday, FOX 2 got a media preview tour of the new features at the Old Courthouse at Gateway Arch National Park in downtown St. Louis.

“It’s built in phases between 1839 and 1862 and built wing by wing,” said Jeremy Sweat, Gateway Arch National Park superintendent. “It wasn’t built in one construction phase.”

May 3 is the grand opening festival.

The project has resulted in the revitalization of the Gateway Arch Park grounds and visitor center, the Museum at the Gateway Arch and much more.

“We were asked to do illustrations for the Dred and Harriot Scott story,” Cbabi Bayouc, an artist, said. “We didn’t know we’d be part of the rebrand and opening in May.”

A number of upgrades, from revitalized courtrooms and exhibits to new glass railings for safety, are not always visible to the naked eye.

“One of the things I like to talk about in the gallery designed for justice is that’s what it was designed for,” said Pam Sanfilippo, Gateway Arch National Park Program manager. “But justice wasn’t always served in this space as well. And those are important stories that we tell here as well.”