The Montana Territory is established under the Organic Act. Governor Sidney Edgerton convenes the legislature in Bannack.

Virginia City becomes the territorial capital.

The territorial capital moves from Virginia City to Helena.

Montana becomes the 41st state on November 8. The decision of the capital’s permanent location is left for the voters to decide; Helena continues its role as temporary capital.

An election is held to determine the capital’s location. Out of the seven cities on the ballot, Helena and Anaconda are the top vote-getters, but neither wins a decisive majority. A runoff is called for.

Helena wins the runoff election and becomes the permanent state capital.

Montana’s Fourth Legislative Assembly authorizes the formation of a five-member Capitol Commission to oversee the design and construction of a Capitol building.

A ground-breaking ceremony is held for the new Capitol.

The Capitol Commission is accused of corruption, and State Representative Fred Whiteside leads the Fifth Legislative Assembly’s investigation. When State Architect John C. Paulsen dies before he can testify, the prosecution is left without its key witness. Without Paulsen, both the Assembly and the Lewis and Clark County Grand Jury find the evidence inconclusive but Governor Robert Smith removes the implicated commissioners.

A new Capitol Commission resumes work on the Capitol, selecting Charles Bell and John Kent’s architectural firm and Joseph Soss’ Butte construction company to complete the building. Bell and Kent relocate to Helena from Iowa to meet the legislature’s demand that the architect of the Capitol be a resident of the state.

The Capitol’s cornerstone is laid on the Fourth of July.

F. Pedretti’s Sons, an Ohio art firm, is chosen to design the Capitol’s interior.

The Capitol is dedicated on July 4.

The Northern Pacific Railroad Company presents Amédée Joullin’s Driving of the Golden Spike to the state as a gift, and the mural is installed inside the arch at the end of the Grand Stairway’s barrel vault.

A bronze plaque honoring veterans of the Spanish-American War is installed.

The Thomas Francis Meagher monument is installed on the Capitol’s north lawn.

The Eleventh Legislative Assembly authorizes construction of additional east and west wings to the Capitol building. A special session of the legislature provides for selection of Montana granite for facing of wings.

Granite from T. Kain and Sons’ quarry at Clancy is chosen over other Kain quarries and other bidders.

Three Montana artists—Ralph E. Decamp, Edgar S. Paxson, and Charles M. Russell—are chosen to paint murals in the new locations of the Law Library, House of Representatives Lobby, and House of Representatives Chamber, respectively.

The Capitol’s new additions and artworks are completed.

The bronze statue of Wilbur Fisk Sanders is completed and installed in the Rotunda.

Capitol building bonds are issued to build an annex on the Capitol’s grounds for the State Board of Health.

Capitol building bonds are issued to construct a vault for the State Treasurer’s Office.

A bronze plaque honoring General John Logan’s Memorial Address is installed as a tribute to Civil War veterans.

Additional paintings by Ralph Decamp are commissioned for the Law Library.

The marble bust of Senator Thomas Walsh is installed in the Rotunda.

The Civil Works Administration does renovation work on the Capitol building.

A series of earthquakes hits the Helena area. The Rotunda’s original glass floor, as well as the walls’ plaster and fresco designs, are damaged.

Works Progress Administration laborers finish repainting the interior of the Capitol building. A faux ashlar design now covers the original Pedretti decorative schemes in much of the Rotunda and second-floor hallways.

The planning phase of a state building program is initiated as part of a postwar planning commission program.

The north entrance on the Capitol’s first floor is constructed.

The Helena firm of Morrison-Maierle and Associates begin work on plans for modernizing the appearance of the Capitol’s interior.

The first stage of modernizing work on the Capitol’s interior is complete.

Stage Two of modernization begins. The Grand Stairway’s stained-glass barrel vault is removed to accommodate the placement of a new fourth-floor hearing room. Joullin’s Driving the Gold Spike is moved to the Rotunda’s west wall.

The west wing is remodeled.

F. A Constitutional Convention produces a new Montana constitution. The bust of former Governor Joseph K. Dixon is installed in the Rotunda.

The bust of former Senator and U.S. District Attorney Burton K. Wheeler is installed in the Rotunda.

The life-size statue of Jeanette Rankin is installed in the south hall of the Rotunda.

Restoration work returns the Capitol’s interior to its original appearance.

The statue of Maureen and Mike Mansfield is installed on the third floor’s south landing.

The bronze relief We Proceeded On is installed in the senate chamber.

The Women Build Montana murals are installed on the third floor’s south landing.