How did the origins of different english accents/dialects that are prevalent throughout north america, englan?

d etc, created? I know about the regional differences - but that doesn't explain how certain places came up with different dialects and accents. For example, I am not from Texas but Canada. I live in Texas and I find that the Texan twang and slurring of words is quite annoying? Why do some Texans sound so weird? They should be able to annunciate words clearly so people from other parts of the country can understand them. Overall, I find all southern accents to be annoying. Please explain to me how people developed the phonetic sounds to say certain words. In a way also perceive the southern draw sound as being lazy and or slow way of talking.