| Date |
Event |
| 100 Million years ago |
Dinosaurs roamed the Dakota landscape. |
| 40,000 - 50,000 years ago |
First humans reached North America. |
| 500 - 1000 |
Mound builders lived throughout much of the midwest, including along the Big Sioux River. |
| 1250 - 1500 |
Mandan-like tribe florished in Missouri River region. |
| 1500s |
Arikara (Ree) migrated northward from Texas seeking relief from drought. |
| 1664 |
Charles II of England granted to James, Duke of York (his brother) all of the land west of the Hudson River (including South Dakota). James never exercised this grant. |
| 1717 |
France granted to John Law all of Louisiana (including South Dakota) with full rights of governing, operating, and protecting the territory. |
| 1720 |
Louisiana reverted to France. |
| 1743 |
Verendrye claimed the Missouri Valley for France. Planted a lead engraved plate at Fort Pierre as proof. |
| 1750 |
"Sioux" tribes move into Dakota. |
| 1762 |
France ceded Louisiana to Spain. |
| 1800 |
Louisiana reverted to France. |
| 1803 |
France sold Louisana to the United States for $3 million. |
| 1804 |
District of Louisiana created, administered by Indiana. Lewis and Clark reach South Dakota. |
| 1812 |
Missouri Territory organized - South Dakota included within its borders. |
| 1817 |
First permanent settlement - Ft. Pierre. |
| 1831 |
Steamboat "Yellowstone" first operated on Missouri River. |
| 1834 |
Michigan Territory organized - extended as far west as the Missouri River. |
| 1836 |
Wisconsin Territory created - extended as far west as the Missouri River. |
| 1838 |
Iowa Territory created - included all lands north of the present state of Missouri between the Mississippi and Missouri Rivers. |
| 1849 |
Minnesota Territory established - included all land north of present state of Iowa between the Mississippi and Missouri Rivers. |
| 1858 |
Minnesota admitted as a state with present boundaries. Dakota orphaned. Treaty with Yankton tribe to buy all their land between the Big Sioux and the Missouri Rivers, except 400,000 acres in the eastern portion of Charles Mix Co., creating the Yankton Sioux Reservation. |
| 1861 |
Dakota Territory created - included everything from the Minnesota border to the Rocky Mountains. |
| 1863 |
First homestead filed in Dakota Territory. |
| 1874 |
Custer discovers gold in Black Hills. |
| 1877 |
Land closed to settlement by President U. S. Grant. Dawes Act passed. Reservations to be broken into 160 acre allotments for Indian farms. |
| 1879 |
Land re-opened for settlement by white people. |
| 1889 |
South Dakota admitted as a state with present boundaries. |
| 1892 - 1904 |
Rosebud Reservation in Gregory Co. thrown open to homesteaders. |
| 1895 |
Excess land in in the Yankton Reservation thrown open to homesteaders. Land sold for up to $3.75 an acre. |
| 1900 |
"Free Homes Bill" becomes law. Surplus lands given to settlers. |
| 1904 |
Pierre becomes the capitol of South Dakota. |
| 1907 |
Surplus lands in Tripp County opened for homesteads. |
| 1908 |
Surplus lands on Cheyenne River and Standing Rock Reservations opened for settlement. |
| 1912 |
Surplus lands in Bennett, Mellette, and Washabaugh Counties opened for homesteads. |
| 1939 |
Badlands made a National Monument. |
| 1941 |
Mt. Rushmore finished. |