1. Nebraska became a state: On September 12, 1867, Nebraska officially became the 37th state in the United States. Its admission marked the end of a long and difficult process that began several years earlier.

2. The first Nebraska State Fair: On September 12, 1868, the first Nebraska State Fair was held in Nebraska City. The fair was a huge success, attracting thousands of people from across the state and featuring exhibits, shows, and competitions showcasing Nebraska's finest agriculture and industry.

3. Omaha hosts a World's Fair: On September 12, 1898, the Trans-Mississippi and International Exposition, also known as the Omaha World's Fair, opened its gates to the public. The fair was a celebration of the cultural and economic achievements of the American West, and featured exhibits from countries around the world.

4. The first Labor Day parade in Lincoln: On September 12, 1892, the first Labor Day parade was held in Lincoln, Nebraska. The parade was organized by the local trades and labor council, and featured floats, speeches, and a band playing the Star-Spangled Banner.

5. The Battle of Liberty Pole: On September 12, 1856, a group of pro-slavery "Border Ruffians" attacked a group of anti-slavery settlers who had gathered near a Liberty Pole near Fort Scott in southeastern Kansas. The ensuing gunfight resulted in two deaths and several injuries, and became a precursor to the larger conflicts that would eventually erupt in "Bleeding Kansas".