Before going too far down this rabbit hole, take a look at John C. Tidball's, The Artillery Service in the War of the Rebellion, 1861 - 1865, Lawrence Kaplan, ed. (Yardley, PA" Westholme, 2011). Tidball, a career Army officer and commander of the Army of the Potomac's 2nd BDE, Horse Artillery, wrote specifically about pistols, sabers, and small arms for the artillery. In short, Redbob is absolutely right. To cite Tidball, the sabers were "soon relegated to innocuous disuse … on the march they soon found their way, with other trash of its kind, to the caissons and carriages .. until dropped from the property returns with the remark, "lost in action". Some sabers were retained for NCOs as badges of authority and those not thus armed were supplied with revolvers.
I hope this helps a bit.