Life expectancy is largely a measure of infant and juvenile mortality.

The founding fathers for example:

• John Adams - 90

• Samuel Adams - 81

• Ben Franklin - 84

• Alexander Hamilton - 49

• John Hancock - 56

• Patrick Henry - 63

• John Jay - 83

• Thomas Jefferson - 83

• Richard Henry Lee - 62

• Robert Livingston - 66

• James Madison - 85

• George Mason - 66

• Robert Morris - 72

• Peyton Randolph - 54

• Roger Sherman - 72

• George Washington - 67

• James Wilson - 55

If you picked a random group of well off Americans today I don't think the ages when they died would look much dissimilar to this.