Today marks one of the most important dates in American history: 150 years ago, Robert E. Lee surrendered the Army of Northern Virginia to Ulysses Grant, and the bloodiest and most wrenching war in America’s history began to wind down.Both men chose wisely that day. Lee understood that the military facts on the ground meant that his army had no reasonable prospect of escaping a destructive and annihilating final battle. More profoundly, he understood that a prolonged guerrilla war, which Confederate die-hards were advocating as an alternative to defeat, would lead to no good. It was time for the war to end, and Lee did what he could to end it.For his part, Grant was already looking ahead. Military victory was in the Union’s grasp; Grant understood that the Union needed to develop a political strategy to begin to knit the country back together. In particular, the terms of the surrender guaranteed that the surrendering Confederate troops could return to their homes where, so long as they remained peaceful, they would not be “molested” by the U.S. government. The Civil War would not be followed by treason trials. Lee and those under his command would return to civilian life.Over the next few weeks, the remaining Confederate armies also surrendered on similar terms. The war ended quickly and, as these things go, cleanly.The subsequent period was not a happy one in American history. The federal government tried and failed to assure the rights of the ex-slaves across the defeated South. Violent resistance, mob rule, and terrorism on the part of the white South succeeded in depriving blacks of their guns, their votes, and their legal and political equality. The North had the will to win a war against slavery, but was neither united enough nor committed enough to the cause of racial equality to hold the South’s feet to the fire, and in the absence of strong support from the north, the South’s African-Americans were unable to defend themselves from the ex-Confederate surge.Americans today look back on the Civil War and Reconstruction with mixed feelings. The preservation of the Union and the abolition of slavery still thrill us; the failures of Reconstruction and the legacy of segregation still weigh heavily on the national conscience and the problems inherited from those years affect us every day of our lives.To some degree, the generous terms that Grant offered the Army of Northern Virginia helped set the stage for the failures of Reconstruction. The choice to build peace by reconciling with the white South rather than forcing a social revolution that would overturn the white elite and provide land to the freed slaves was already implicit in Grant’s promise that the defeated officers and men could return to normal life after the war.But even knowing this, it is hard to argue that Grant should have behaved any differently. Ending the war had to be his first priority; offering generous terms to the Army of Northern Virginia undermined the will of the remaining Confederate armies and commanders in the field. The South would ultimately turn to something like a guerrilla war in its fight against equal rights for blacks; when that happened, public opinion in the North soon wearied of the frustrating tasks of counter-insurgency and nation-building. Getting the Confederate armies to disband, and ensuring the cooperation of leading white southerners like Lee was Grant’s smartest choice in April, 1865.