1. Oregon became a state on May 15, 1859 - It was on this day that Oregon became the 33rd state to join the Union. This significant event marked the end of a long process that began when Oregon was first settled by Europeans in the 18th century.

2. The first car in Oregon was purchased on May 15, 1899 - On this day, George Armbuster bought a one-horsepower Oldsmobile from the W.B. Ayer Company in Portland. The car cost $650 and had a top speed of 25 miles per hour.

3. The first public library in Oregon opened on May 15, 1902 - The Portland Public Library was created by the City Council on this day, and it opened its doors to the public less than a year later. Today, the library has over 700,000 books and other materials.

4. The first legal same-sex marriage in Oregon was performed on May 15, 2014 - After a federal judge overturned Oregon's constitutional amendment banning same-sex marriage, the first couple to receive a marriage license under the new law got married on this day.

5. The Oregon Territory was established on May 15, 1848 - The United States Congress created the Oregon Territory, which included present-day Oregon, Washington, Idaho, and parts of Montana and Wyoming. The territory was divided into smaller states over time, leading to the formation of the state of Oregon.