Superbowl of Logos... History of the Seahawks & Patriots Logos

On February 1, Super Bowl XLIX ("49" for those of us who don't quite get Roman numerals) will take place, and over 63,000 fans will converge on the University of Phoenix Stadium in Arizona. Many of those fans will be sporting the logos of the New England Patriots orSeattle Seahawks. But how did those logos get to us? How were they designed?