On 4 May 1964, the U.S. Congress recognized Bourbon Whiskey as a “distinctive product of the United States," creating the Federal Standards of Identity for Bourbon. Federal regulations now stipulate that Bourbon must meet these requirements:
In practice, almost all bourbons marketed today are made from more than two-thirds corn, have been aged at least four years, and do qualify as "straight bourbon"—with or without the "straight bourbon" label. The exceptions are inexpensive commodity brands of bourbon aged only three years and pre-mixed cocktails made with bourbon aged the minimum two
it was named for bourbon county kentucky, but unlike say champaigne or socth, is not require to be from that reigion.
and to clearify Jack Daniels, its sour mash is les then 51 % corn