Emperor Gia Long unified Vietnam by conquering Hanoi.
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Marvel's 'Avengers: Endgame' became the most financially successful movie of all time.
33-year-old Katharine Lee Bates wrote the famous song 'America the Beautiful.'
Palermo, Sicily was liberated by US forces.
American serial killer Jeffrey Dahmer admitted to murdering 17 people.
The Mariner 1 Space Probe was forced to self-destruct minutes after launching.
