CONCORD, N.H. — The golden dome atop the New Hampshire State House is glistening once again.

Workers have begun to dismantle the scaffolding around the dome on the Civil War-era capitol. Started in March and expected to be completed by Dec. 1, the $1 million project has involved meticulously laying 5 pounds of gold leaf in 4-inch squares on the dome and its golden eagle. The dome had been tarnished over the years and had not been refurbished since the late 1990s.

“That dome is the symbol of the state to a very large degree,” House Speaker Shawn Jasper said. “It was looking pretty sad and shabby, and now it’s shining brightly.”

The 500,000-pound, 90-foot tower of scaffolding has been reduced to 30 feet, leaving the fresh gilding visible. Workers are now replacing rotted wood and windows on the octagonal lantern that sits below.

The project is “quite a feat,” said Ted Kupper, administrator in the division of public works, which oversees maintenance of historical buildings.

The original dome was similar to a silo and perched on top, according to the State House Visitor’s Center. The dome was enlarged as part of a project to expand the State House during the Civil War. It was modeled after the 17th-century dome atop the church of the Hotel des Invalides in Paris.

An eagle has been perched atop the dome since 1819, though a wooden one was replaced by a copper replica in 1957.

The dome’s makeover comes to an end as the state launches a three-year-long bicentennial celebration of the State House and its grounds. The state is also opening the building on select weekends this fall. The bicentennial kickoff on Sept. 24 launched with a laying of a cornerstone to mark 200 years from the day ground was broken to build the State House. The celebration will run through June 2019, the 200th anniversary of the opening of the capitol.

New Hampshire is one of 13 states with a golden dome, and it’s not the only source of pride on the State House grounds. The New Hampshire House is the oldest legislative body in the country that still meets in its original chambers. At one time, the state’s supreme court even met inside the complex, as well.

The State House steps have been the stomping grounds of many a political candidate through the years, including a large “fall kick-off rally” for Hillary Clinton in 2007 for her first presidential run.

During the first seconds of 2008, when civil unions became legal in the state, dozens of gay and lesbian couples bundled up against freezing temperatures held a group ceremony on the steps. In January 1986, many gathered there for a memorial service for Concord High School teacher Christa McAuliffe, who perished with six astronauts when the space shuttle Challenger broke apart on live TV. The year before that, President Ronald Reagan spoke there about tax reform.

“There are people who spoke in that State House, who made laws in that State House who were alive and fought in the American revolution,” said Rep. Renny Cushing, chairman of the State House Bicentennial Commission. “We want to highlight the State House itself, because it is kind of a symbol of our democracy in New Hampshire.”

The three-year celebration will feature educational and historical events, including a plan by the state Supreme Court to hold oral arguments in the State House chambers where it used to meet.

And for at least one night, the shining golden eagle atop the dome will have to share its spotlight with the wooden eagle that preceded it.

One of the milestones in State House history, Cushing said, was a celebration on the plaza in the early 1800s to place the wooden eagle atop the dome. Revelers gathered on the lawn to drink and celebrate the eagle, and the bicentennial commission is planning to take the wooden eagle from the state historical society for re-creation of the night.

Back then, Cushing said, “they had a rousing time on the plaza out in front where they celebrated a toast to the eagle.”