1830 Mary had a little lamb first published
1844 Samuel Morse sends the first telegraph mesage
1883 the Brooklyn Bridge opens
1930 Amy Johnson becomes the first lady to fly from England to Australia, having set off a mere 20 days earlier.
Bermuda Day 2016 (first weekday after 24 May: people go into the sea and start wearing Bermuda shorts to work)
Saints Cyril and Methodius, Slavonic Enlighteners Day: these 9th-century Greek Christian missionaries invented the Cyrillic alphabets so they could write to and convert the illiterate pagan Slavs in what is now the Czech Republic, Hungary, Austria, Croatia, Serbia, Slovenia, Slovakia and Bosnia and Herzegovina. This day is celebrated in Bulgaria and Macedonia.
Eritrea Independence Day (from Ethiopia in 1991; Eritrea originally formed after Italy and the Ottoman Empire pushed a bunch of independent kingdoms into one country, and it became part of Ethiopia in 1947.)
Belize Commonwealth Day
Battle of Pichincha (Ecuador, 1822 against Spain)