1. In 1887, the Montana State Legislature passed a bill designating January 21 as "Lee-Jackson Day" in honor of Confederate generals Robert E. Lee and Stonewall Jackson. The holiday remained on the calendar until 2015, when it was officially replaced with Martin Luther King Jr. Day.

2. On January 21, 1904, the town of Terry in eastern Montana recorded a low temperature of -57 degrees Fahrenheit, the coldest ever recorded in the state.

3. Montana State University, located in Bozeman, was founded on January 21, 1893, as the Agricultural College of the State of Montana. The school is now a leading research and educational institution, offering undergraduate and graduate programs in a variety of fields.

4. In 1914, the Anaconda Copper Mining Company opened its first smelter in Great Falls, Montana. The smelter operated for nearly 70 years, producing copper and other metals until it was closed in 1980.

5. On January 21, 1936, the Anaconda Mine Disaster occurred near Butte, Montana, when a fire broke out in an underground shaft, killing 23 miners. The disaster remains one of the deadliest mining accidents in Montana's history.