William M. Mitchell
... that William M. Mitchell is believed to be the only writer to document the Underground Railroad while it was still illegal?
... that <b id="mwCwg"><a href="./William_M._Mitchell" id="mwCwk" rel="mw:WikiLink" title="William M. Mitchell">William M. Mitchell</a></b> is believed to be the only writer to document the <a href="./Underground_Railroad" id="mwCwo" rel="mw:WikiLink" title="Underground Railroad">Underground Railroad</a> while it was still illegal?