1. The famous horse race, the Kentucky Oaks, is traditionally held on the first Friday in May, which often falls on or close to May 3rd. The first running of the Kentucky Oaks took place in 1875, and it is now considered to be one of the most prestigious races for fillies in the world.

2. In 1937, a massive tornado outbreak swept across portions of the southern and eastern United States, including Kentucky. On May 3rd of that year, Kentucky was hit by 22 tornadoes, causing widespread destruction and resulting in more than 240 fatalities.

3. May 3rd is also the anniversary of the birth of Mary Breckinridge, a nurse and midwife who founded the Frontier Nursing Service in eastern Kentucky in 1925. The service provided vital healthcare and birthing assistance to women and families living in rural areas of Kentucky.

4. In 1941, the Ford Motor Company opened a massive factory in Louisville, Kentucky, which produced B-24 Liberator bomber planes during World War II. The factory was one of the largest in the world, covering over a million square feet of space, and employed tens of thousands of workers.

5. On May 3rd, 1800, the Kentucky General Assembly passed a law establishing the Kentucky Historical Society, which is still in existence today. The society's mission is to collect, preserve, and share the history of Kentucky and its people, and it operates a museum, library, and research center in Frankfort, Kentucky.