1. In 1846, the first ferry service was established across the Platte River in Nebraska City. The ferry operated until 1854 when a bridge was built over the river.

2. On April 16, 1860, the first Pony Express riders arrived in Sacramento, California, after a journey that started in St. Joseph, Missouri, on April 3. The Pony Express was a fast mail delivery service that operated for only 18 months before being replaced by the transcontinental telegraph.

3. In 1879, the Nebraska Legislature passed a law establishing Arbor Day as a holiday on April 22. Arbor Day is a day set aside to plant trees and raise awareness of the importance of trees for the environment.

4. On April 16, 1917, Nebraska Governor Keith Neville signed a law prohibiting the manufacture, sale, or transportation of alcohol in the state. The law came into effect when the 18th Amendment to the US Constitution was ratified, which prohibited the sale and consumption of alcohol nationwide.

5. In 1960, farmer Roscoe Filley of Auburn, Nebraska, invented the Center-Pivot Irrigation system, changing the way farmers irrigate their crops. The system uses a rotating sprinkler head that waters crops in a circular pattern, increasing yields and reducing water waste. The Center-Pivot Irrigation system is now used all over the world.