Regional Dialects in America are heavily influenced by past heritage and culture of that specific region.
According to John B. Bushman's article on Scholarworks.edu, early settlers in the North, South, and Mid-Atlantic have distinctive dialects that have transformed into a regional identities. Dialects are a very evident characteristic of a certain place. So, as one is raised in an area, they learn their local dialect of the English language. With everyone in a region knowing the same dialect, it becomes an identity of a place. Bushman also noted that because America is a land of different people,there are many many different languages translated into English. So, a word may have a different meaning from language to language and from place to place. This varying of definitions is an example of varying dialects. In this particular situation, dialects differ in languages as well as region.
The Dialects of American English" found on pandora.cii.www.edu was an enlightening source of information. This site listed the factors of American dialects as.....
The fact that in 1629 the Puritans fled to Massachusetts for religious freedom is well known. But, also in this process, the Puritans brought their "twang" flat -sounding dialect to American soil. Following the precedent set by the Puritans back in 1629, the region of the Massachusetts area, New England, is still very rich in this distinctive dialect.
Another fact given by this article is that British Royalists left southern England during the 1st English Civil War, and as they moved, their dialect came with them. The "drawl" dialect came to the Carolina's, becoming known as the Coastal Southern Dialect.
Going now to the middle of the country, the General English Dialect can be found right in the heart of America. This dialect is often referred to as the standard form of English. This dialect became very prominent after the U.S. Civil war.
My last source, dialectblog.com, decides to focus on the Western American Dialects and where they are located. Because of their proximity to the Canadian border, Northwestern speakers in states such as Washington, Montana, and Idaho have a touch of Canadian accent and dialect. The reason for this mix of language factors can be found simply on the map. Because these areas are close to each other, it is only natural for its people to mix in some way.
On the other hand, the Central and Southern part of the Western United States contain a bit of influence from the Southern dialect. The Southern dialect stretches over areas such as Texas, Oklahoma, Arkansas and Mississippi and also out west to states like New Mexico and Arizona.
To figure out where your own speech choices would put you on the dialect map, click the link below to take a quiz.
Bushman, John H.. "Exploring the Geographical Dialects of English." <i></i>. N.p., 1 Jan. 1989. Web. 27 May 2014. <http://scholarworks.gvsu.edu/cgi/viewcontent.cgi?article=1680&context=lajm&sei-redir=1&referer=http%3A%2F%2Fwww.google.com%2Furl%3Fsa%3Dt%26rct%3Dj%26q>
Trawick-Smith, Ben . "American Accents and Dialects." <i></i>. N.p., 1 Jan. 2011. Web. 27 May 2014. <http://dialectblog.com/northamerican-accents/>.
"The Dialects of American English." <i></i>. N.p., n.d. Web. 27 May 2014. <http://pandora.cii.wwu.edu/vajda/ling201/test3materials/AmericanDialects.htm>.