I can confirm this, and when I look at the files, they are consistent with what happens: Pinkerton is the last leader the union receives (from May 63), and he's also the last listed in Events/USA Leaders.sct.

Thank you for that. I had a hunch he was disappearing due to his presidential run, but I would suggest that it appears in the messages on the bottom right.

Maybe I have overlooked something, but I can't find any messages. I think it starts happening in 1864: McClellan disappears. Historically he ran for president in 1864, which may be the reason; he does disappear in 1864, but it seems to happen randomly, i.e. not tied to a specific turn. I'm playing t...