7 March 1876: Alexander Graham Bell gets his telephone patent

The US Patent Office granted Alexander Graham Bell patent number 174,465 for the telephone, beating rival Elisha Gray in one of history's most famous patent disputes. Western Union passed on buying the patent, a decision that ranks among the great business blunders. Bell's invention became the foundation of AT&T, which for much of the 20th century was the most widely held stock in America.

The lesson: Turning down a revolutionary technology because it seems like a toy can be a historic mistake.