I was reading a few blogs today that mentioned that today is the anniversary of the date that Soviet cosmonaut Yuri Alekseyevich Gagarin became the first human being to travel into space back in 1961.
Today is also the anniversary of the launching of the first space shuttle, exactly 20 years later, back in 1981. The Space Shuttle Columbia was the very first reusable craft to travel into space.
Today is also the anniversary of the day that FDR died, in 1945, shortly before Hitler's Germany was defeated in World War II. He presided as President for over 12 years, dying three months into his fourth term. His presidency was the reason for the creation of the 22nd Amendment, limiting the office of the President to two consecutive elected terms.
Most interestingly for me, today marks the anniversary of the start of the American Civil War, on April 12th, 1861, at Ft. Sumter in South Carolina. The war dragged on for four years and was the bloodiest four years in American history. I've also had a strong interest in the American Civil War, always doing extra reading on it for history class, and later in life learning that I had relatives who fought on both sides of the conflict (although mostly for the South, it turns out).
There was even an article in an old Dragon magazine about a campaign that could include "sophisticated" elven cavaliers fighting against urban industrialized dwarves. Even though it seemed kind of silly, I liked that article a lot as a kid and it did help to fire my imagination about how to take the standard fantasy tropes and turn them upside down. (As a side note, I would love to tell you which issue of Dragon it was, but after spending over 20 minutes searching online and even trying to go through my PDFs from my Dragon CD-ROM collection, I gave up. All of this technology and nobody can do a decent index for Dragon magazine articles).
Civil wars play a somewhat important role in my current World of Samoth campaign. There are currently several wars going on, and while many of them are between different countries, there is one major one that's self-contained in a country called Verundhi where the established ruling class in the North is slowly losing ground to a group of rebel upstarts in the South who seem to be getting magical help of a... less than savory nature.
There's also a type of "civil war" happening in one of my major monotheistic religions, as the more hard-line elements of the Church have taken it upon themselves to actually arm troops and cross a political border to track down and kill a group of "heretics" (dwarves, who don't follow the religion). This has sparked a continent-spanning war between two different sides, even though they both claim to follow the same religion.
So there you go - hopefully a little historical inspiration for your games.