<P> In 1862 the war became much more bloody, though neither side was able to gain a lasting strategic advantage over the other . However, the decisive battles of Gettysburg in the east and Vicksburg in the west allowed the momentum of the war to shift in favor of the Union in 1863 . Increasingly, Confederate forces were outmatched by the more numerous and better equipped Union forces, whose greater population and economic resources became critical factors as the war became one of attrition . An increasingly effective naval blockade further damaged the Southern war economy . </P> <P> By 1864, long - term Union advantages in geography, manpower, industry, finance, political organization and transportation were overwhelming the Confederacy . Grant fought a remarkable series of bloody battles with Lee in Virginia in the summer of 1864 . Lee's defensive tactics resulted in higher casualties for Grant's army, but Lee lost strategically overall as he could not replace his casualties and was forced to retreat into trenches around his capital, Richmond, Virginia . Meanwhile, in the West, William Tecumseh Sherman captured Atlanta in 1864 . His March to the Sea destroyed a hundred - mile - wide swath of Georgia, with little Confederate resistance . In 1865, the Confederacy collapsed after Lee surrendered to Grant at Appomattox Courthouse . </P> <P> In all, 2.2 million men served in the Union army; 360,000 of whom died from all causes--two - thirds from disease . The Volunteer Army was demobilized in summer 1865 . </P> <P> While the Confederacy suffered from a worsening lack of adequate supplies, the Union forces typically had enough food, supplies, ammunition and weapons . The Union supply system, even as it penetrated deeper into the South, maintained its efficiency . The key leader was Quartermaster General Montgomery C. Meigs . Union quartermasters were responsible for most of the $3 billion spent for the war . They operated out of sixteen major depots, which formed the basis of the system of procurement and supply throughout the war . As the war expanded, operation of these depots became much more complex, with an overlapping and interweaving relationship between the Army and government operated factories, private factories, and numerous middlemen . The purchase of goods and services through contracts supervised by the quartermasters accounted for most of federal military expenditures, apart from the wages of the soldiers . The quartermasters supervised their own soldiers, and cooperated closely with state officials, manufacturers and wholesalers trying to sell directly to the army; and representatives of civilian workers looking for higher pay at government factories . The complex system was closely monitored by congressmen anxious to ensure that their districts won their share of contracts . </P>

Who became the leader for professionalism and training of the regular army post 1814