Anyone with more than a passing interest in history will have at one point amused themselves by asking the question, "What would have happened if...?" In what way would the history of the world be different if Archimedes had not met his untimely demise? Stuff like that.
So the site Today in Alternate History is really cool. It's written as a blog, with what (might have) happened on this day in various years, according to several different alternate time-lines.
For example, for today (it's actually yesterday, what with different time-zones, but let's not worry about that) they have (among other things) the USA being renamed the "Soviet States of America" in 1948. If you check their page of recurring time-lines, you will see that this all arises from Karl Marx moving to America in 1843...
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