So this is a common question/source of argument.
Bourbon does not need to come from Kentucky!
Bourbon, or bourbon whiskey, can, in fact, come from any of the 50 states.
It must be made in the U.S., consist of at least 50% corn mash, be aged in new, charred, American oak barrels, and meet certain requirements for alcohol content at various points in its processing.
It is true that it takes its name from Bourbon County, Kentucky, and that most bourbon, and almost all well known brands or bourbon, are from Kentucky. There is also a designation, Kentucky Straight Bourbon, which applies only to bourbon produced in Kentucky.
People often ask why there isn't more bourbon out there from other parts of the country if it doesn't have to come from Kentucky. My best answer is three fold:
1) Convenience. Corn and the other grains commonly used in bourbon grow easily, and are available relatively locally, without the cost of transport, in Kentucky. There are also facilities in which to mash, ferment, and distill bourbon already in place, as well as rackhouses to age the bourbon in.
2) Competition. When there are already so many good bourbons coming from Kentucky, it is difficult to compete. Especially when so many people think that all bourbon, or all good bourbon, has to be from Kentucky.
3) Perception/marketing. Because of the stereotype most people hold of bourbon coming from Kentucky, as well as the fact that there is a law allowing Kentucky bourbons to be labeled as "Kentucky Straight Bourbon," it is easier and more logical to market a bourbon as being from Kentucky than as not being from Kentucky. A lot of branding behind bourbon also has to do with tying it to its Southern, and in particular Kentucky, roots. So you may have seen a bourbon made outside of Kentucky, and not even realized it, just assuming from the label and the spirit type, that it was a Kentucky bourbon.
