1. On January 23, 1939, the Mount Rushmore National Memorial was officially declared complete after 14 years of carving the sculptures of four American presidents - George Washington, Thomas Jefferson, Theodore Roosevelt, and Abraham Lincoln - into the granite face of the mountain.

2. In 1906, the South Dakota Legislature authorized the establishment of the state's first tuberculosis sanatorium to help combat the deadly illness that had become rampant in the state. The state sanatorium at Custer opened on January 23, 1912, and remained in use until 1964.

3. The Black Hills Stock Show and Rodeo, one of the largest agricultural and livestock shows in the nation, was first held in Rapid City on January 23, 1959. The event features a variety of livestock exhibits, rodeo performances, and other agricultural competitions and educational activities.

4. On January 23, 1929, the South Dakota State House of Representatives cast the decisive vote to ratify the 19th Amendment to the U.S. Constitution, which granted women the right to vote nationwide. South Dakota became the 19th state to ratify the amendment.

5. In the 1860s, the discovery of gold in the Black Hills region led to a rush of settlers and miners into the area, which was then part of the Dakota Territory. On January 23, 1874, a group of prospectors led by Lt. Colonel George Armstrong Custer discovered gold in the French Creek area, setting off a second wave of gold rushes in the Black Hills.