The Wisconsin State Capitol sits in the center of the Capitol Park, located atop a hilltop on an isthmus formed by lakes Monona and Mendota. The nine and one-half acre landscaped grounds forming the square remains at the center of the original historic plat of Madison, designed in 1836 by James Duane Doty and surveyor J.V. Suydam. The current, granite faced, Beaux-Arts style building is the third on the site, and the fourth capitol building of Wisconsin.

After the second Madison capitol building burned in 1903, various plans were explored for the Capitol. In 1905, the Capitol Commission established a program for the new building, requiring that it be in the form of a cross, with the four equal wings of the building radiating to the corners of the square. The prominent New York firm of George B. Post and Sons was awarded the contract for the building's design. In 1906 ground was broken for the construction of the West Wing. Construction was carried out in five phases over eleven years; the massive dome crowning the building was completed in 1915 and the building itself was finished in 1917.

The building is noted for its decorative program. Sculptural groupings are found at each of the four wings and at the level of the dome. Nationally prominent artists worked on various decorative features of the building. Atop the dome's lantern is "Wisconsin," a gilded bronze statue by sculptor Daniel Chester French, who is best known for the gigantic seated figure of Abraham Lincoln in the Lincoln Memorial in Washington. The interior is enriched with a variety of marble and granite finishes. The interior of the dome was painted by Edwin Bashfield and the wall areas supporting the dome are decorated with mosaic panels executed by muralist and painter Kenyon Cox. Principal rooms and chambers throughout the building are also elaborately decorated.

In addition to its significance as a fine example of the Beaux-Arts style and as a work of architect George Post, the Wisconsin State Capitol has important associations with the Progressive Movement in the early decades of the twentieth century. Governor Phillip La Follette's contributions to social reform include model legislation for unemployment compensation and for an increased governmental role in economic planning. The capitol building was also the home of the Legislative Reference Library, an outgrowth of the "Wisconsin Idea," the concept that knowledge gathered by the research efforts of university faculty should be utilized to improve the lives of the citizens of the state.

The plan of the building, which provides access from the four corners of the Capitol Square, combined with the decorative program of the building, which celebrates good government, gives architectural form to Wisconsin's governmental ideals. The building continues to serve the three branches of government and is open to the public.