[3] In 1854, the General Assembly decreed a location “within two miles of the Raccoon fork of the Des Moines River.” The exact spot was chosen when Wilson Alexander Scott gave the state nine and one-half acres where the Capitol now stands.

In 1870, the General Assembly established a Capitol commission including local businessman and politician Peter A. Dey to employ an architect, choose a plan for a building (not to cost more than $1.5 million), and proceed with the work, but only by using funds available without increasing the tax rate.

A major restoration was performed and documented, with the addition of electrical lighting, elevators, and a telephone system.

[4] While its primary use is as the house of the legislative branch of Iowa government, the Capitol also functions as a living museum and state and international cultural facility.

Since 1987, the World Food Prize laureate award ceremony is held annually in October in the House of Representatives chamber of the statehouse.

[7] The architectural design of the Capitol, rectangular in form, with great windows and high ceilings, follows the traditional pattern of 19th-century planning for public buildings.

The superstructure, or main part of the building, is of bluff colored sandstone from quarries along the Mississippi River in Missouri.

The commanding feature is the central towering dome constructed of iron and brick and covered with tissue-paper thin sheets of pure 23-carat gold.

[5] The dome is surmounted by a lookout lantern that may be reached by long and winding stairs, and it terminates in a finial that is 275 ft (84 m) above the ground floor.

Walls are highly decorated and the rooms and chambers of the capitol have a wide variety of Iowa wood as well as imported marble.

Twenty-nine types of imported and domestic marble were used in the interior; and the wood used—walnut, cherry, catalpa, butternut, and oak—was nearly all from Iowa forests.

The Victorian-styled Law Library features four stories of balcony shelves surrounding a central atrium and is open to the public on weekdays.

Extending the full width of the east wall over the staircase is the great mural painting Westward, an idealized representation of the coming of the people who made Iowa.

Edwin H. Blashfield, the artist, wrote of it: "The main idea of the picture is a symbolical presentation of the Pioneers led by the spirits of Civilization and Enlightenment to the conquest by cultivation of the Great West.

"[4] In the central rotunda, suspended beneath the ceiling on wires is a very large banner of the insignia of the Grand Army of the Republic, which between 1894 and 1953 had a room in the state capitol dedicated for their use.

On July 7, 2012, the retired Iowa opened to the public as a floating educational and naval museum at the Port of Los Angeles in San Pedro, California.

In the south hall across from the Governor's office is a collection of porcelain dolls representing the 41 Iowa First Ladies in miniature replicas of their inaugural gowns.

A two-week display of Baphomet and the seven tenets of the Satanic Temple was set up, with official approval, in the Iowa Capitol in December 2023.