While Lee's surrender at Appomatax did help pave the way for the military side of the Lost Cause (i.e. the idea that the North only won because numbers and industrial capacity), he was against the sort of memorial glorification of the confederacy that serves as a key part of the lost cause today.
The irony of ironies: It happened despite Lee's wishes!
Thinking about Appomattox in this context always brings me back to Jay Winik's April 1865. Winik is making argument that the United States really was reborn in the spring of 1865 at Appomattox, and Durham, and Citronelle, and, well, Lincoln's presidential locus, since that's where the policy that made these amicable surrenders possible was really decided - or, at least, enabled. But more immediately it reads to me like an encomium to Grant and Lee. Grant, for being so generous in offering terms; Lee, for actually accepting them. Because there was nothing inevitable about either. A quick glance around the rest of the western world in the 19th and early 20th centuries will tell you that. And Americans of those generations did the glancing.
Over the past decade, it's come to look like less of a great deal, because the focus now is so often on the price that deal came with, which was a century of Jim Crow, and its attendant legacy. I don't think we should be so ready to accept the argument that that price of Appomattox was inevitable, but I am open to the idea that it became considerably more probable. And I think there's a sense in which @Red_Galiray is taking that...probability as read, which is why I think he's exploring a harder war and a harder termination to increase the probability of getting instead a Reconstruction that's actually worthy of the name, rather than trying to thread some post-Appomattox needle. And I find this project fascinating to watch unfold, because it's seldom been explored.
I think the only concern I have been trying to get at in my last few posts is the risks that come with a hard war/hard peace trajectory like this. It unleashes furies deep in human hearts you may not find so easy to control. And this would be the case not just among southern bitter-enders, but a lot of Northerners, too. You can put yourself in the place of Lincoln, or his successor, and work out the ideal Reconstruction plan, but that doesn't mean you'll be able to keep control of the politics, or the armies, to consummate it. Think about Thaddeus Stevens and his idea of Reconstruction, as laid out in his September 1865 address in Lancaster. He advocated treating the South as conquered provinces, where the Constitution would have no effect; this would make it possible for the government to confiscate the estates of the largest 70,000 landholders there, those who owned more than 200 acres. Most of this property he wanted distributed in plots of 40 acres to the freedmen (no mention of a mule, but maybe that was in the footnotes); other lands would go to reward loyalists. Now, that wouldn't hit too many white yeoman farmers; but maybe it's not so hard to imagine events unfolding such that demands that the confiscations go a lot deeper, maybe to every single property owner who fought for the CSA, and you're unable to stop those demands. Before long, maybe, you've got a Cromwellian resolution dropping in your lap, and even Thaddeus Stevens starts to look like a bleeding heart. Cromwell made his resolution stick, to be sure, but aside from the, uh, immediate genocide, it required the enforcement at bayonet point of an Anglo-Irish military caste habituated into treating the surviving natives as something like vermin for the next 265 years.
Of course, that would be a fascinating timeline to read, too...