The Army Corps of Engineers played a significant role in the American Civil War. Many of the men who would serve in the top leadership in this organization were West Point graduates. Several rose to military fame and power during the Civil War. Some examples include Union generals George McClellan, Henry Halleck, and George Meade; and Confederate generals Robert E. Lee, Joseph Johnston, and P.G.T. Beauregard. The versatility of officers in the Army Corps of Engineers contributed to the success of numerous missions throughout the Civil War. They were responsible for building pontoon and railroad bridges, forts and batteries, destroying enemy supply lines (including railroads), and constructing roads for the movement of troops and supplies. Both sides recognized the critical work of engineers. On 6 March 1861, once the South had seceded from the Union, its legislature passed an act to create a Confederate Corps of Engineers.