I ran some numbers using this savings calculator: 
http://www.dinkytown.net/java/CompoundSavings.html

Assume you deposited $7,000 for a baby and left it in an account paying 8% interest and made no additional contributions. You would have $1,891,819 after 70 years. Of course that's in today's dollars. Inflation will significantly erode the buying power of that amount over 70 years.

Also, 8% is a very optimistic rate or return. I would go with 6%, in which case you would wind up with only $467,000 (that 2% really makes a difference)!  

I suspect that small amount of money, after 70 years of inflation, will not adequately provide for the needs of most retirees.