From oldest to youngest, all prize same values

The year that the two oldest companies on our list of Top 100 Privately Held Companies were founded, Alexander Graham Bell patented the telephone, Custer and the 7th Cavalry were wiped out at Little Bighorn, and Colorado had just become America's 38th state.

When the youngest company on our list started up, thenPresident Bill Clinton was impeached, a federal judge found computer giant Microsoft Corp. to be a monopoly, and the nation was worriedly bracing for Y2K.

Despite their 12-decade age difference, the leaders of our oldest and youngest firms agreed that the keys to running a profitable and successful business never change. The best firms emphasize customer service and …