1642 Harvard College graduated its first class. No witches. None there the semester I was there either.
1806 Meriwether Lewis and William Clarke returned after three years in the wilderness without GPS but with Sacagawea. Part of the trip was along the River Platte.
1846 Berlin Observatory observes Neptune, right where it was supposed to be. Famous for its storms now as shown below.
1884 Herman Hollerith patented a tabulating machine. The start of the pocket calculator.
1932 Saudi Arabia became Saudi Arabia. [Witticism needed.]