Yes, it's that day again--International Leftanders' Day! Today is the 35th such special day for left handers (although some might say that every day is special if you are left handed!)
I don't know why this day, the 13th of August, was selected. It is the birthday of Fidel Castro, but that is probably just a coincidence. Some sources say Fidel is left handed--for example he is on the University of Indiana Famous Left-Handers list. But images on the web show him batting and writing rightie. He may be a leftist, but not with respect to laterality.
Of the many other mildly famous and obscure people born on this day (Don Ho? Lucy Stone? Ben Hogan?) none is a Great Left Handed Person, as far as I can tell.
August 13th is the anniversary of the great Arica earthquake in 1868. Possibly caused by a left hander?
On August 13th, 1918, Opha Mae Johnson became the first woman to enlist in the United States Marine Corps. As far as I know she was not left handed.
The closing of the border and start of construction of what was to become the Berlin Wall was on 13 August 1961. The Leftist German Democratic Republic wanted to keep both left handed and right handed East Germans from moving to Rightist West Berlin. Not really a great day for left handers or anyone else.
So I guess International Lefthanders' Day was established on 13th August mainly because it seemed like a good idea and no other major holidays or festivals already occupied the spot. As good a day as any!
So Happy International Lefthanders' Day, all you left handers! Let's march in solidarity in any and all International Lefthanders' Day parades (stepping off with the left foot, as is traditional). If there is not an International Lefthanders' Day parade in your area, maybe you could organize one for August 13th next year.