Atop the Capitol

While the seat of state government at 2nd and Monroe in Springfield has been closed to visitors since mid-March by the coronavirus outbreak, residents and visitors to the capital city still have the Capitol building and its distinctive dome as a familiar sight on Springfield’s cityscape.

It won’t be long before legislators and members of the public once again gather beneath the dome. They will be keeping alive a long tradition: for nearly 150 years, the dome of the Illinois State Capitol building has welcomed visitors and residents alike as they arrive in the capital city.

Illinois’ first three capitol buildings were simple structures. The fourth such building, in Vandalia, was the first to feature a cupola atop its roof. A more rounded design was incorporated into the cupola of the state’s fifth capitol when it was built in Springfield in the 1830s. But it was hastily outgrown and the General Assembly began the process of building a new Capitol just after the Civil War.

The architect, John C. Cochrane, put forward a much more grand and ambitious design. The building would feature a dome unlike any other: larger even than the newly-constructed dome over the national Capitol building in Washington. For submitting the winning design, Cochrane won a $3000 prize. He would eventually be joined in the project by architects Alfred Piquenard and William Boyington.

Construction of the Capitol building at 2nd and Monroe in Springfield began in October 1868. By the mid-1870s, the building itself was constructed, but work had not yet begun on that portion of the dome which would tower over it. Photos from this time period inspire a double-take in those who view them today: the familiar building without its most recognizable feature.

But this description is slightly misleading: for while the dome is not yet visible in photos from the 1870s, it was in fact well under construction. The foundation for the dome is contained within and below the building: a 92.5 foot circular foundation built upon solid rock more than 25 feet below ground level. The walls which rise from this rock to support the enormous weight of the dome are 17 feet thick at their base up through the first floor.

By 1876 enough progress had been made on the dome that the Stars and Stripes could be displayed atop it for the first time (albeit from a construction crane): celebrating Washington’s Birthday in the nation’s centennial year. The first time the flag flew from its own dome-top flagpole was that November. Electric lights were installed in 1877 to illuminate the building from the outside, but no electric lights were installed inside until the 1890s. The dome was completed in 1887. On New Year’s Day it was lit with 144 gas jets, while a series of gas lamps were used to brighten the skylight.

The completed dome stands 361 feet above the ground, with the tip of the flagpole rising to 405 feet – 117 feet taller than the height of the Statue of Freedom atop the U.S. Capitol in Washington. Illinois’ capitol is the tallest domed capitol building in the nation, and is only behind the office tower-style capitols in Louisiana and Nebraska in overall height.

A common sight within the Capitol building is the groups of tourists who stand in the middle of the rotunda near the Illinois Welcoming the World statue and look straight up at the ornate inside of the dome. But in fact, this is not the top of the dome. It is instead a dome-within-a-dome. The inner dome, complete with its state seal skylight 223 feet above the floor, is housed within the outer dome. The skylight is lit by natural light entering through the circle of glass windows which surround it. Sharp-eyed observers will note an extra letter in the state motto contained within the state seal in the skylight: an extra “i” in the word “sovereignity.” Above this inner dome is a spiral staircase leading to an observation deck at the top of the outer dome.

The cleverness of this dome-within-a-dome design was made clear to all in September 1911 when a severe thunderstorm caused significant wind damage to the outer shell of the dome, breaking windows and tearing off parts of the skin of the dome. Interior damage to the building was light by comparison. This round of damage and the resulting repairs would not be the last.

Storm damage was just one of the many reasons for renovations and updates to the dome over the years. Some of the first Secretaries of State to take charge of the new building in their dual role as custodian of the Capitol had to deal with water leaking through parts of the dome. One of these, Henry Dement, who served from 1881 to 1885 was particularly vexed by birds roosting in the dome. He was observed climbing to the Capitol roof with a shotgun to scare the birds away.

By 1931, the half-century old dome was in need of repair. The General Assembly hired Frank Randall, a Chicago structural engineer to inspect the dome and recommend any needed improvements. He came back with a long list. One of the top items he suggested was the replacement of all the wood used in constructing the dome with materials that would stand up better against a fire. This would prove prophetic just two years later.

A large crane and wooden scaffold were erected at the building’s southwest corner to allow workers to access the exterior of the dome. Work was also done on its interior, which is mostly made of brick, with the outside supported by iron trusses. It was also around this time that the previously-accessible dome was closed to public tours. Another innovation became essential in the 1932 renovation, one which could not have been foreseen by the architects in the 1860s: a flashing anti-collision light for aircraft.

Eventually, the entire exterior shell of the dome was removed and replaced in 1932. Workers from the firm of W.M. Allen and Sons worked through the fall and winter to replace the dome’s outer shell. They finished their work the following year, but as with any large building, construction and repair were never truly completed. In 1957 the Capitol saw its first million-dollar renovation. The dome’s outer skin was replaced again in 1975 at a cost of $850,000. Late last year, small crumbles of concrete were found between the two domes, causing inspectors to rappel all along the outside of the dome to check for cracks or other damage over the course of two days in December.

The artwork of the interior dome is breathtaking to behold, but gradually over the Capitol’s first century it became less and less so. Over the decades, soot and grime accumulated on the inside of the dome and proved very hard to remove. As the Capitol’s centenary approached in the 1980s, most of the artwork on the inside of the dome had been completely lost to view. In 1983, renovations began on the outside of the Capitol building, and a special renovation project was begun specifically for the dome in August 1986. The 1986 renovation, which cost $1.3 million, was the first wholesale reworking of the inside of the dome since its completion in the 1880s. A display on the Capitol’s 2nd floor recounts the story of the work.

Just getting to the surfaces to be restored took some engineering. Workers in a basket were suspended from the top of the iron and zinc dome and secured with ropes to whichever portion of the inner dome required their attention that particular day. For heavier work, a platform was built 115 feet above the floor of the rotunda. A photo of this delicate balancing act is found in the 1987 Illinois Blue Book.

The inside of the dome is encircled by two dozen plaster columns, each 43 feet in height. These columns were re-plastered and then “marbleized” to make them appear to be made of marble. The project also called for the application of 350 gallons of paint to the dome. The inner dome contains 9000 pieces of stained glass, each of which had to be removed and cleaned.

As the work progressed, artwork was rediscovered and restored. Windows were cleaned, surfaces were repainted, grime was removed and the dome was restored to its original splendor. A plaster frieze, eight feet in height and painted bronze, circles the base of the dome. It portrays scenes from American and Illinois history, starting with the period just before the Revolution and extending to the Lincoln-Douglas debates which occurred a decade before ground was broken for the Capitol.

The dome has been the subject of many rumors and legends over the years. One prominent legend in Springfield is that the local police department once used an emergency beacon atop the Capitol to summon officers in the days before squad cars were equipped with two-way radios. The legend has it that any officer who saw the light flashing atop the dome would then report to the nearest call box and contact the police station for instructions.

Whether the emergency light story is true or not, the dome has been the center of many spectacular light shows over the years, including its bright illumination to celebrate early 20th-century gubernatorial inaugurations. Today its most celebrated light show is the annual Christmas lights display in which strands of lights are extended from the top of the dome to the far corners of each wing of the Capitol, giving the entire building the appearance of a large, brightly-lit Christmas tree.

Upon the completion of the 1986 renovation, the Secretary of State’s office proudly boasted, “with proper care, the Illinois Capitol will stand for another century meeting the ever-changing needs of state government while retaining its historic character.”


For more information on the history of the Illinois Capitol, including photos from throughout its 150 years, visit