1792 - First guillotine is used to execute a highway robber
1859 - Construction begins on the Suez Canal
1915 - ANZAC troops land at Gallipoli during World War 1
1959 - St. Lawrence Seaway construction is completed
1990 - Violeta Barrios de Chamorro is sworn in as President of Nicaragua
1990 - Hubble Space Telescope begins operation
Summaries: (these are not robust or containing all important details; Don't @ me)
1792 - The guillotine was invented by Antoine Louis and Tobias Schmidt as a means of capital punishment that would quickly end a life and inflict as little pain as possible. The first execution using the guillotine was the death of highwayman Nicolas Jacques Pelletier, which solidified its place as the only execution tool for decades to come.
1859 - Construction began on the Suez Canal and would not be completed until 1869.
1915 - Australian and New Zealand Army Corps (ANZAC) troops landed at the beaches of Gallipoli within the Ottoman Empire, beginning the Gallipoli Campaign. The goal was to continually advance North to Istanbul and take the Ottoman Capital. The campaign was a massive failure for the Allies, resulting in 56,707 Allied deaths (31,389 British, 9000 French, 8709 Australian, 3431 New Zealand; estimated) and 56,643 Ottoman deaths.
1959 - St. Lawrence Seaway is completed, linking the Atlantic Ocean to the Great Lakes allowing much larger ships to bring cargo in and out of the Mid-Western states and Canada. It is one of the largest feats of engineering ever finished.
1990 - Violeta Barrios de Chamorro is sworn in as President of Nicaragua, making her the first head of state in Central America. She served from 1990 to 1997. This marked the first peaceful transfer of power in Nicaragua in over 5 decades.
1990 - Hubble Space Telescope was placed into orbit by the crew of Space Shuttle Discovery. It would later begin its service May 30th, and continues to operate today.