Not to fight too much with Stealth Munchkin, but country music/country & western is descended from medieval Gaelic/English folk music. (Irish + Scottish = Gaelic for my purposes), and not the Blues, which is the secular descendent of the "negro spiritual," the religious descendent being Gospel.

When one examines the instrumentation (for example, the prominence of bowed instruments), rhythm, melodic structure, and subject matter of country music, one can see its simliarities to the folk music of the British Isles. This is no surprise, as the people who played country music were primarily descended of the Isles, living in the South and the Ozarks--areas where the white population was more English and Scotch-Irish than any other European ethnic group. Bring in square dancing--the Virginia Reel is nothing but the remains of Gaelic jigs and reels.