In this video, Atun-Shei claims, "By the end of the war, many Union soldiers did consider their cause to be abolitionist. This was mainly because of the large number of contraband slaves that would follow Union armies wherever they went. And these Yankee boys, many of whom had never been to the South in their lives, were being confronted by the horrifying realities of slavery for the very first time. This hardened their hearts against that institution, and they said as much in their diaries and letters."

To what extent is this true? Was the general consensus among Union soldiers that they are also fighting for abolition? What was the response among Union soldiers upon learning of the Emancipation Proclamation? How did Union veterans react to the 13th, 14th, and 15th Amendments? Did they see these as the fruits of their labor or the culmination of their efforts? Was there a sense of pride, shame, or something else among Union veteran soldiers for their role in achieving these milestone pieces of legislation?

Thanks for your time. :) If you have any recommendations for books to learn about the common person's thoughts during the Civil War, I'd be very interested. Collections of diaries, letters, etc. are of particular interest to me.