Good points Doyle. Despite potentially severe consequences, many Union soldiers did quit over Lincoln's so-called emancipation of slaves and riots ensued in major yankee cities.
And yes, Lafayette knew damn well what was at stake in the First American Revolution and he understood tyranny. Here is another one of his quotes.
“Humanity has won its battle. Liberty now has a country.”
Then, he had that epiphany and realized there was slavery here as well as France.