The story of the nation’s capital — from the ground up — is the subject of a new exhibit opening Saturday at the National Building Museum.

“Washington: Symbol and City” explores the underlying “tension between local and federal interests” at the heart of much of the city’s physical development, said Curator Don Hawkins.

In the works for more than two years, the exhibit takes its name from an earlier show at the museum that closed four years ago, Hawkins said. Initially, the museum had planned to perform some maintenance work in the gallery and update that exhibit’s materials, but ultimately decided to “do an entirely new one,” he said.

“In spite of the weaknesses of the city, of being essentially powerless in the face of Congress … we have shaped a unique city, a city with a great deal of vitality and variety,” Hawkins said.

The first portion of the exhibit examines the evolution of the “city of intent,” or those parts of the district that the federal government designed to “symbolize a Republican democracy,” he said.

Two models of the National Mall (one of the Mall as it was in 1901 and another as the McMillan Commission envisioned it to be) are surrounded by four tactile models depicting the Capitol, the White House and the Jefferson and Lincoln memorials.

“It’s as if you were in the space,” said Rebecca Fuller, who created the plexiglass and cast urethane models, which stand 1/60th their actual size. “It’s exactly the same axis as in real life.”

In the remaining two galleries, which highlight the “evolving city,” an elongated display structure cuts a diagonal slice through the rooms reminiscent of Pennsylvania Avenue in an effort to remind “you of things without saying them directly,” said Hawkins.

Among the stories related to Pennsylvania Avenue’s changing face is that of the development of Federal Triangle, formerly “a mid-city slum” surrounded by “small industry” as well as the “most notorious and longest continual red-light district in the city” prior to its leveling at the onset of the Great Depression, said Hawkins. The exhibit also takes a look at the broader implications of the FBI building’s construction along the avenue in the wake of the 1968 race riots.

Before 1972, the FBI occupied the upper floors of office buildings throughout downtown Washington, said Hawkins, “so when they moved into the building … shortly after the riots had occurred … downtown which was in bad shape suddenly got a lot worse.

“The District had no power to consider the effect,” he noted.

Hawkins added that the original design of the building had called for commercial shops to line the structure’s Pennsylvania Avenue side, but then-FBI Director J. Edgar “Hoover himself didn’t trust the ladies who came into the dress shop not to blow up his building.”

“Now it doesn’t sound as silly. … He was just way ahead of his time in his paranoias.”

“Washington: Symbol and City,” which opens Oct. 9, will be on display indefinitely at the National Building Museum. For more information, go to www.nbm.org.