The Egyptians, Greeks, and Romans raised statues to honor and celebrate their best. Their best scholars, best generals, and best leaders. Do you know what the Romans did to the statues of Emperaers especially the ones like Caligula, Commodus, Nero and Domitian who failed them and committed atrocities??? They erased them from history. It was called Damnatio memoriae or "condemnation of memory," meaning that a person must not be remembered or celebrated. They tore their statues down and erased their names from public record because they were not to be celebrated but to be ashamed of. Monuments aren't historical.
Monuments are celebratory. And 150 years later the South is still determined to celebrate its lost cause. A Rebellion that they started not because of states rights which was never mentioned in any of their secession declarations but because of Slavery. For too long Southerners have attempted to hide the experience and motivation for the Confederates to secede from the Union. They are inseparable. Armies of Rebels and traitors who broke their oaths to their country and broke faith with the Union don't get nor do they deserve monuments to their defeat. Only the victors do. And lets not forget the sole reason that these statues were erected in the first place during the 1920s -1960s. To remind African Americans living through Jim Crow and Segregation of who was still in charge and slavery or not they would still find ways to oppress them.
Have you ever thought of the parallel between the Revolution and the Civil War? That both were fought by people who opposed legitimate rule? Have you ever read this quote?
"Any people anywhere, being inclined and having the power, have the right to rise up, and shake off the existing government, and form a new one that suits them better. This is a most valuable - a most sacred right - a right, which we hope and believe, is to liberate the world."
The author was Abraham Lincoln. He was, of course, talking about what is now Texas and Mexico at the time - a conflict in which many southern and northern generals fought side by side. History doesn't alter the achievements of participants, but opinions do, and it's primarily based on who won or lost.
Whether you want or choose to believe it, southern generals like Lee were no less patriots than Washington - and probably far better men than Grant, but they were anti federalists. There was an ongoing struggle between federalists and those who believed in primary governance by the individual states from the time of secession/revolution with Britain.
The shame of it all is that we didn't learn much from that struggle. We are still forcing federalism - trying to make 300+ million people see everything one way rather than letting states tailor even mundane issues to more regional wishes. You realize that what fits in NY or NJ isn't going to work well in Montana or New Mexico because conditions are radically different - population density for starters.
People in DC are still stubbornly hammering squares into round holes and fracturing the edges. Does that mean we revert to policies of the past? No, things do change with time; policies of the past may have been acceptable to people at the time, and in a hundred years it's likely that some of today's accepted practices will be viewed as absurd, immoral, barbaric, ...