Stephen, you are absolutely correct that we should try to see things through the eyes of those who actually lived those events.

For example, attitudes about slavery and racial inferiority were much, much different then than now. I don't think it's fair, or historically accurate, to judge our ancestors harshly by today's standards. Back in the 1860's, the world was only just beginning to reassess the morality of slavery. It would take nearly a century before attitudes about racial inferiority would undergo a similar reassessment.

It's a natural human process to view things through the prism of our own experiences. It's the mark of a good historical researcher to overcome that tendency to the extent possible.