I find your discussion about Hobart Walker very interesting. My Great-Great Grandmother was Hobart's sister Emma Walker. I have been interested in Hobart's military service for almost twenty years. I am curious what your relationship is within the Walker family.
My understanding of why Hobart was on the General Lyons that night was that they were moving Confederate prisoners to NY. I know his father Ferdinand spent many months trying to get information on his son's death. I believe the General Lyons was out of Hart Island, NY, which was a prisoner of war camp in 1865. At least that is where Ferdinand was directing all his inquires about his son's death too.
I would welcome a further discussion on any Hobart Walker related topics if you are so inclined.