Answer:
The previous answer is true. The origin of the slogan is actually my grandfather, Gerry Woodward, former VP of marketing for the PNW Bell Corp. My mother and uncle vividly remember him dropping his fork at dinner in astonishment when the slogan finally popped into his head. It went on to become one of the most recognizable slogans is US history (http://adage.com/century/slogans.html). He also was extremely influential in the choice to use 9-1-1 as the emergency number of the country. He elected the number for use and earned the use of the number based on usage facts of old rotary phones. A smart man and a good role model, we all miss him.
What the author did not know is Grandfather Gerry Woodward had a dirty little secret, he did not in fact come up with this slogan on his own. PNW Bell had a management class bringing in employees from many locations. As part of this class each participant was to come up with 10 different slogans. One participant Eva-Mae Martin from Longview Washington, came up with the slogan and art work during the class as her final entry. The only acknowledgment she ever received was a Thank You for coming and sent back to Longview.