In 1878, two years after Alexander Graham Bell invented the telephone, the first telephone exchange became operational. A month later, the first telephone directory was printed by the New Haven Telephone Company. It was simply one piece of white card. On it was printed 50 listings. The headings were divided into four sections: residential, professional, miscellaneous and essential service listings. Early directories only listed names; numbers were not needed because operators made the connections for each caller.
The reason that now it is called the Yellow Pages, is not sure. The earliest trace of the term was when the printers ran out of white paper in 1883, and used yellow instead. Later research showed that black on yellow were the easiest colours to read, other than black on white.
In 1886 Reuben H. Donnelly printed the first Yellow Pages to categorize business names and numbers by the types of service they offered. As telephone service spread across the nation, the Yellow Pages industry grew. In 1909, St. Louis produced the first Yellow Pages directory with coupons.