1. In 1889, the Oklahoma Land Run began on April 22 and continued for several days, but many people began to gather at the border on April 18 in anticipation of the event.

2. On April 18, 1906, the largest earthquake in Oklahoma history occurred near Tulsa. The earthquake, which measured 5.5 on the Richter Scale, caused widespread damage and was felt as far away as St. Louis, Missouri.

3. On April 18, 1942, the United States began relocating Japanese-Americans from the West Coast to internment camps, including those living in Oklahoma. Nearly 120,000 people of Japanese ancestry were forced to leave their homes and businesses and were held in camps for the duration of World War II.

4. In 1951, the Oklahoma City National Memorial Museum was dedicated on April 18, the sixth anniversary of the Oklahoma City bombing. The museum commemorates the 168 people who lost their lives in the bombing and serves as a tribute to those who survived.

5. On April 18, 2007, severe storms and tornadoes caused significant damage across central and eastern Oklahoma. The storms produced hail larger than baseballs and caused power outages for thousands of residents. Several tornadoes touched down, including an EF2 tornado that struck the town of Durant.