Trench warfare
Trench warfare has become archetypically associated with the First World War of 1914–1918, when the Race to the Sea rapidly expanded trench use on the Western Front starting in September 1914. By the end of October 1914 the whole front in Belgium and France had solidified into lines of trenches, which lasted until the last weeks of the war. Mass infantry assaults were futile in the face of artillery fire as well as rapid rifle and machine-gun fire. Both sides concentrated on breaking up enemy attacks and on protecting their own troops by digging deep into the ground. Trench warfare also took place on other fronts, including in Italy and at Gallipoli.
Robert E. Lee
Grant eventually was able to stealthily move his army across the James River. After stopping a Union attempt to capture Petersburg, Virginia, a vital railroad link supplying Richmond, Lee's men built elaborate trenches and were besieged in Petersburg, a development which presaged the trench warfare of World War I. Lee attempted to break the stalemate by sending Jubal A. Early on a raid through the Shenandoah Valley to Washington, D.C., but Early was defeated early on by the superior forces of Philip Sheridan. The Siege of Petersburg lasted from June 1864 until March 1865, with Lee's outnumbered and poorly supplied army shrinking daily because of desertions by disheartened Confederates.