To gain support for the revolutionaries. The story was exaggerated, but the American people bought it. It was used as a recruitment/propaganda campaign to turn as many people against the British occupation as possible.
Tradition
They like to keep tradition going
Florence was the most famous. :)
It made a split between the North and the South economically because the North was advancing more, while the South thought the best market was slavery and cotton. Which ultimately led to the Civil War.
