South Dakota History: Statehood, Mount Rushmore, and Its Flag

South Dakota became a state on November 2, 1889, sharing its birthday with North Dakota. Its history reaches much further back than that signature and much further forward than the frontier. Native communities, homesteaders, miners, military families, farmers, entrepreneurs and scientists have all shaped the state whose flag carries the words “The Mount Rushmore State.”

Understanding that history gives the flag greater meaning. It represents an American state built through work and self-government, but also a place where broken treaties, economic hardship and struggles over citizenship tested the nation's promises. There is room for honest remembrance alongside pride in service, constitutional liberty and the people who keep their communities strong.

Statehood: November 2, 1889 · Conventional admission order: 40th · First state flag: 1909 · Current flag wording: 1992

Explore: Before statehood · Becoming a state · Building and changing South Dakota · The modern state · Flag history · Timeline · Choosing and displaying a flag

Before South Dakota: Native homelands and the Missouri River

People lived in this landscape thousands of years before the United States existed. Archaeological work in Badlands National Park has identified a site more than 12,000 years old. Seasonal camps, hunting sites and stoneworking places reveal long familiarity with the plains, not an empty country waiting to be discovered. The National Park Service's archaeology overview also explains the limits of the evidence: the park's record does not establish permanent settlement within its present boundaries.

Across the wider region, societies and economies differed. The Arikara, who call themselves Sahnish, maintained fortified earthlodge villages along the Missouri. When Lewis and Clark traveled through in 1804, three Arikara villages stood near the Grand River in present-day northern South Dakota. Farming communities participated in regional trade as well as hunting; epidemics and displacement later disrupted these settlements. Their history belongs to the living story of the Arikara people, not simply to an archaeological past.

The tribal map changed over time. Arikara, Mandan and Cheyenne communities occupied parts of central South Dakota, while Lakota people moved westward during the eighteenth century. Dakota and Lakota histories are closely connected, but their communities should not be treated as interchangeable. European trade goods, trading posts and fur companies increasingly connected the Missouri country to distant markets. The South Dakota State Historical Society documents these overlapping histories of settlement, trade and movement.

Treaties, settlement and Dakota Territory

The Louisiana Purchase brought American claims to the region in 1803. It did not erase Native nations or resolve ownership on the ground. Decades of diplomacy, commercial expansion and military pressure followed. Under the 1858 Yankton treaty, the Yankton ceded extensive lands in southeastern present-day South Dakota and retained a reservation along the Missouri. The agreement helped open the southeast to non-Native settlement.

Congress organized Dakota Territory on March 2, 1861. It initially covered both present-day Dakotas and portions of what became Montana and Wyoming. Territorial status meant that residents lacked the full political standing of a state and that the president appointed important territorial officials.

In the west, the 1868 Fort Laramie Treaty established the Great Sioux Reservation, including the Black Hills. The discovery of gold by the 1874 Custer expedition helped unleash a rush into land protected by that treaty. Mining settlements expanded, conflict intensified, and the federal government took the Black Hills in 1877. Gold helped build a major regional economy, but the manner in which the land was taken remains essential to understanding its history and its sacred importance to Lakota people.

Why two Dakotas became states in 1889

Statehood was a long campaign rather than a single ceremonial day. Southern Dakota held constitutional conventions in 1883 and 1885 before the successful 1889 process. An attempted state organization could not substitute for congressional admission. Meanwhile, the 1883 transfer of the territorial capital from Yankton to Bismarck sharpened southern dissatisfaction.

Distance, competing commercial and railroad connections, and the desire for locally accountable government all encouraged division. National party politics mattered too. Republicans expected support from Dakota voters, while Democrats worried about the balance of power in Congress. The eventual agreement admitted two Dakotas along with Montana and Washington rather than leaving the territorial dispute unresolved. The State Historical Society of North Dakota's account explains these regional and political pressures.

President Grover Cleveland signed the enabling legislation on February 22, 1889. Delegates met that summer, and voters approved South Dakota's constitution in October. President Benjamin Harrison proclaimed admission on November 2. The U.S. Senate's South Dakota timeline distinguishes these two presidential actions.

South Dakota is conventionally numbered the 40th state and North Dakota the 39th. That does not establish which proclamation Harrison actually signed first. The signing order was deliberately obscured, and the states are generally listed alphabetically. As North Dakota's official state history explains, the exact order is unknown. Both states can rightly celebrate November 2.

Self-government, constitutional rights and civic responsibility

Statehood gave South Dakotans greater authority over their own public affairs within the American constitutional system. The state's Bill of Rights protects religious conscience, due process and the right of citizens to bear arms in defense of themselves and the state. It also places political power in the people and recognizes the supremacy of the U.S. Constitution.

Those principles offer a strong foundation for limited, accountable government. They also ask something of citizens: respect for other people's rights, lawful conduct and the willingness to shoulder responsibility. Responsible gun ownership fits that tradition through safety, training and respect for the law. Pride in freedom is strongest when paired with the discipline needed to preserve it.

Homesteads, opportunity and the cost of expansion

Admission did not end settlement. The Homestead Act of 1862 had offered a route to landownership through residence and improvement, and later laws enlarged claims in some areas. Railroad construction continued opening markets after statehood. In the Badlands, the arrival of rail service at Interior in 1907 helped encourage another wave of homesteading. Families faced isolation, scarce water and the challenge of making a living in an unforgiving climate. The National Park Service's homesteading history places these efforts alongside the allotment and loss of Native lands that made much expansion possible.

Opportunity attracted people with very different backgrounds. Oscar Micheaux, a Black homesteader who settled in South Dakota in 1904, turned experiences on the plains into books and then a pioneering film career. Drought undermined his farm, but his writing opened another path. His life connects South Dakota's agricultural frontier to American literature, entrepreneurship and Black cinema. Micheaux's story broadens the familiar image of who sought independence on the prairie.

The early statehood years also include a national tragedy. On December 29, 1890, U.S. Army troops killed hundreds of Lakota people at Wounded Knee on the Pine Ridge Reservation, including women and children. The deaths occurred amid military efforts to suppress the Ghost Dance movement and disarm Big Foot's band. Estimates differ, and the number buried in the mass grave should not be mistaken for the total killed. The National Historic Landmark documentation examines this history and the evidence. Remembering Wounded Knee honestly is part of taking America's promises seriously.

Expanding participation in public life

South Dakota became the first state to adopt statewide initiative and referendum in 1898, giving voters a direct role in proposing laws and reviewing legislation. That innovation reflected distrust of concentrated political power and a determination to make government answerable to citizens. The Secretary of State's ballot-measure history identifies this national first.

The franchise itself remained contested. Women could participate in school elections before statehood, but the 1889 constitution limited the general vote to men. Repeated campaigns followed. In 1918, voters approved an amendment that removed the male-only restriction while also requiring U.S. citizenship. South Dakota ratified the Nineteenth Amendment in December 1919, ahead of its national adoption in 1920. The history of the state's suffrage movement shows how years of organizing changed constitutional practice.

Depression, conservation and a monument in the Black Hills

For farm families, economic distress began before the 1929 stock-market crash. Falling agricultural prices, debt and bank failures weakened rural communities during the 1920s. The 1930s added drought, dust storms and grasshoppers. Foreclosure could destroy the independence a family had spent years building. The state's historic study of postwar South Dakota traces these earlier pressures and the population changes they helped produce.

Relief and conservation work left physical legacies. Civilian Conservation Corps crews at Wind Cave built roads, improved visitor facilities and worked on the cave's infrastructure. Their wages also supported families at home. These projects offered practical work during a national emergency, as documented in Wind Cave's CCC history.

Another project transformed the Black Hills' public identity. Mount Rushmore grew from state historian Doane Robinson's tourism proposal and sculptor Gutzon Borglum's vision. Carving began in 1927, supported by political advocates and federal funding; work ended in 1941. Washington, Jefferson, Theodore Roosevelt and Lincoln became a monumental statement about American leadership. The memorial's history also belongs within the longer story of the Black Hills. Appreciating its patriotic purpose need not require ignoring the land's significance to Native people.

War, agriculture and the remaking of the Missouri

World War II brought military service and renewed demand for agricultural production. Afterward, mechanization and farm consolidation changed the countryside, while employment and population increasingly concentrated in towns and cities. The state preservation study documents this transition from Depression hardship toward a different postwar economy.

During the Cold War, South Dakota also became part of the nation's nuclear deterrent. Missile fields placed local ranchland and military installations within a worldwide strategic system. Today, Minuteman Missile National Historic Site preserves the experiences of service members and surrounding communities. It is a reminder that national defense depends on sustained readiness and responsible service, including duties that receive little public attention.

The Flood Control Act of 1944 authorized the Pick-Sloan program, which reshaped the Missouri through dams and reservoirs. The projects brought flood control and hydroelectric power, but their costs fell unevenly. Reservoirs inundated reservation lands, homes, timber and culturally important places. Oahe alone took more than 104,000 acres from the Cheyenne River Sioux Reservation and roughly 56,000 from Standing Rock. A Government Accountability Office history explains the losses and subsequent compensation legislation. A complete account must include both the infrastructure's benefits and the communities required to give up so much.

Disaster, protest and a changing modern economy

On June 9–10, 1972, catastrophic flooding in the Black Hills killed 238 people. Rapid City suffered especially severe destruction. Recovery changed how the city used vulnerable land, including development of a greenway along Rapid Creek. The U.S. Geological Survey's account connects the disaster to later warning systems and floodplain planning.

In 1973, Wounded Knee again drew national attention. American Indian Movement members and supporters occupied the community amid disputes over tribal leadership and demands concerning federal treaty obligations. The 71-day confrontation left two Native men dead and others wounded. The U.S. Marshals' account and AP's anniversary reporting document different aspects of an event whose legacy remains contested.

Economic change took several directions. Citibank's relocation of its credit-card operations to Sioux Falls in 1981 helped establish a major financial-services presence, a milestone recorded in Citi's institutional history. At Lead, the former Homestake gold mine acquired a new purpose as the Sanford Underground Research Facility. A site associated with mineral extraction became a center for experiments investigating fundamental physics. Excavation for the Long-Baseline Neutrino Facility and Deep Underground Neutrino Experiment reached a major completion milestone in 2024; that did not mean the entire experiment was operating. Sanford Lab's history traces the transition.

Agriculture remains central. USDA's 2025 South Dakota overview, checked in October 2026, reports 28,200 farm operations and 42.2 million acres in farms. Native communities likewise remain an essential part of the present: South Dakota's judicial system identifies nine federally recognized tribes with their own sovereign court systems. Today's state cannot be understood solely through either its frontier past or its best-known monument.

South Dakota's flag: 1909 origins and later changes

The date 1889 on the seal marks statehood, not the flag's adoption. South Dakota's first state flag appeared in 1909. Designed by Ida Anding, later Ida McNeil, it placed a sun on one side and the state seal on the other.

In 1963, the design brought the seal and sun together, reducing the difficulty and expense of producing two distinct faces. In 1992, “The Mount Rushmore State” replaced “The Sunshine State.” The State Historical Society's flag exhibit text explains this sequence. Older Sunshine State flags can therefore illustrate a genuine historical design, rather than a printing error; state law also preserves official recognition for qualifying earlier flags.

Today's flag has a sky-blue field, the state seal surrounded by gold sun rays, and gold lettering naming South Dakota and its Mount Rushmore identity. Inside the seal, a farmer, livestock, crops, a riverboat, mountains and industrial activity portray productive life. The motto, “Under God the People Rule,” joins a declaration of popular government to the state's religious heritage. The Secretary of State's explanation of the seal and flag provides the official description.

The combined design makes a useful historical lesson: the seal recalls admission and nineteenth-century livelihoods, while the surrounding words reflect a landmark completed generations later.

South Dakota history at a glance

• Before European settlement: Native peoples develop enduring communities, trade networks and relationships with the plains and Missouri River.
• 1861: Congress creates Dakota Territory.
• 1868–1877: The Fort Laramie Treaty protects the Black Hills; gold-driven conflict is followed by federal seizure.
• November 2, 1889: South Dakota enters the Union.
• 1890: The Wounded Knee massacre occurs.
• 1898: South Dakota adopts statewide initiative and referendum.
• 1909: The first state flag is adopted.
• 1918: Voters approve women's general suffrage.
• 1927–1941: Mount Rushmore is carved.
• 1944 onward: Pick-Sloan dams transform the Missouri and neighboring communities.
• 1963: The flag brings the seal and sun together.
• 1972–1973: The Black Hills flood and Wounded Knee occupation mark difficult chapters.
• 1981: Citibank brings credit-card operations to Sioux Falls.
• 1992: The flag receives its Mount Rushmore State wording.
• 2024: A major underground excavation milestone advances neutrino research at Sanford Lab.

Choosing and displaying a South Dakota flag

A statehood birthday, veterans' event, classroom lesson or everyday home display can all be occasions to fly South Dakota's flag. When it shares a pole with the U.S. flag, place the American flag above it. On equal-height poles in a straight line, give the U.S. flag its own right-hand position of honor. The Secretary of State's display guide explains these arrangements.

Before purchasing, match the flag to its use. Check dimensions, fabric, attachment style and the product's stated indoor or outdoor suitability. A grommeted flag and a sleeve-mounted flag need different hardware. Inspect outdoor flags regularly, and follow the manufacturer's care guidance rather than assuming any fabric is indestructible.

Explore South Dakota flags at FORTISVEX, and use our state birthdays guide to connect your display with the wider American story. Flying the flag with knowledge honors more than a date: it honors the work, sacrifice and responsibilities that come with self-government.