<P> September 1 , 1997 - August 25 , 2015 ( main series ) </P>
<P> September 1 , 1997 - August 25 , 2015 ( main series ) </P>
when did the captain underpants books come out
when did the captain underpants books come out
September 1 , 1997
September 1 , 1997