Because issues that my peoples faced over a century ago, do not affect me in my life in 2015.
If I am in a good relationship with a decent woman, couldn't care less who she dated in the past and certainly wouldn't say or think "Oh I cant date this woman, because she dated men whose forefathers were devils"
If you wanna let issues that from over a century ago affect you in 2015, then that's up to you.
If the girl is good for you, you gonna throw her to the bushes due to your way of thinking of incidents that occurred over 100 years ago ? Seems very strange to me and cant really relate to this way of thinking.
Find a good girl, keep her, simple.