In the current Harper's no less a writer than Lewis Lapham references the
quote "usually attributed to Mark Twain that although history doesn't repeat
itself, it rhymes."  At least he qualifies his use of this truism, but that
still implies that it could be authentic, and I find nothing that sources
this quote to Twain before 1995.

Has anyone sourced it to, oh... say, before April, 1910?

Befuzzled, and with fantods,

Kevin Mac Donnell
Austin TX