1. The first steamboat to navigate the Yellowstone River arrived in the Dakota Territory on July 23, 1832. It was called the Yellowstone, and it made it all the way to the mouth of the Bighorn River before it had to turn back due to the shallow conditions.

2. On July 23, 1863, the Battle of Big Mound took place in what is now North Dakota. It was the first battle of the Dakota War of 1862-1865, and it saw a small group of Dakota soldiers clash with a larger force of U.S. Army soldiers, who were pursuing them. Several soldiers were wounded on both sides, but there were no fatalities.

3. July 23, 1889, was the day that the last spike was driven into the Northern Pacific Railroad at Gold Creek, Montana. This railroad had a significant impact on North Dakota, as it made transportation and commerce much easier and more efficient.

4. The first airplane to land in Fargo, North Dakota, touched down on July 23, 1911. It was a monoplane flown by a man named Frank Bryant, and he had to make an emergency landing in a farmer's field due to engine trouble. The plane was quickly repaired and Bryant was able to continue his journey a few days later.

5. On July 23, 1951, President Harry Truman signed an executive order temporarily closing all mines in the Turtle Mountain district of North Dakota due to unsafe conditions. The mines had a long history of fatalities and accidents, and the order was an attempt to make them safer for workers.