Humanities faculty love.
I didn't major in History (I intended to) but I love it so I've taken a handful of courses as electives and hope to take at least one or two more next year (couldn't fit any in this year *cries*). Anyway overall I've really enjoyed them and feel Mac has some top notch History professors, very knowledgeable and passionate about the field. Again though I didn't major in it so I can't comment on the courses as a major in the program.
It does seem like it would be a heavy work load but if you love it and you feel you can handle the reading, researching and essay load then you're headed in the right direction.
I took the History courses b/c I love the subject matter but they have always been my most time consuming and work heavy courses and I haven't received As across the board in them, but I can't say it would be the same for you.
To give you an idea of the course variety here is the History course calendar for 2009-2010:
http://registrar.mcmaster.ca /calen...nt/pg1800.html
You can read a brief explanation of each History course Mac has at the present moment.
Hopefully a History major can give you more details.