Here is a great quote on this celebration of America’s independance from one of it’s founding fathers.

" I observed on one of the drums belonging to the marines being raised that there was painted a rattlesnake with this modest motto under it "dont tread on me". It occurred to me that the rattlesnake, being found in no other quarter of the world besides America, might therefore be chosen to represent her. Having frequently seen the rattlesnake I ran over in my mind every property by which she was distinguished. I recollect that her eye excelled in brightness that of any other animal, and that she has no eye lids, she may therefore be esteemed an emblem of vigilance. She never begins an attack, nor when once engaged never surrenders, she is therefore en emblem of magnanimity and true courage. As if anxious to prevent all pretentions of quarreling with her the weapons with which nature has furnished her she conceals in the roof of her mouth, so that to those unacquainted with her she appears to be a most defenseless animal and even when they are shown and extended for her defense they appear weak and contemptible, but their wounds however small are decisive and fatal. Conscious of this she never wounds until she has generously given notice even to her enemy and cautioned him against the danger of treading on her. I counted the rattles … and found them just 13, exact the number of colonies united in America, and I recollected too, that this was the only part of the snake that increases in numbers. … Tis curious and amazing to observe how distinct and independent of each other the rattles of this animal are and yet how firmly they are united together so as to never be separated but by breaking them to pieces. One of those rattles singly is incapable of producing sound, but the ringing of thirteen together is sufficient to alarm the boldest man living. The rattlesnake is solitary and associates with her kind only when it is necessary for their preservation. In winter the warmth of a number together will preserve their lives, while singly they would probably perish. The power of fascination attributed to her by her a generous construction may be understood to mean that those who consider the liberty and blessing which America affords and once come over to her never afterwards leave her, but spend their lives with her. She strongly resembles America in this, that she is beautiful in youth and her beauty increaseth with her age, her tongue is blue and forked as the lightning, and her abode is among impenetrable rocks. "

 - Benjamin Franklin (From the Completed Autobiography)