1865 – Lincoln assassin John Wilkes Booth dies
http://www.history.com/this-day-in-history/lincoln-assassin-john-wilkes-booth-dies
1954 – Polio vaccine trials begin
http://www.history.com/this-day-in-history/polio-vaccine-trials-begin
1986 – Maria Shriver marries Arnold Schwarzenegger
http://www.history.com/this-day-in-history/maria-shriver-marries-arnold-schwarzenegger
1986 – Nuclear disaster at Chernobyl
http://www.history.com/this-day-in-history/nuclear-disaster-at-chernobyl
2013 – Country music star George Jones dies
http://www.history.com/this-day-in-history/country-music-star-george-jones-dies