Giving POWER back to the PEOPLE…
Now to return to the question of the stripes' orientation. The flag represents the US government, or some agency or aspect of it. By convention, horizontal stripes denote the US government in a military capacity. Vertical stripes, and there have been several flags that actually had vertical stripes, were adopted to denote the government in a civil capacity. So the version of the flag that currently prevails is the military version.
http://www.answers.com/Q/Why_do_the_stripes_on_a_flag_go_horizontal_not_vertical