In response to K.Klassy‘s question, yes, there is an Underground Freedom Train again this year to celebrate Emancipation Day. Friday, July 31, 2015 at 11pm at Union Station, Ticket Booth. Train departs @ 11:30 p.m.
and arrives at Downsview Station: August 1, 2015 Emancipation Day.
For what happened last year, click on: https://www.youtube.com/watch?v=fA4M_dOyb4Q