of July 2, a massive attack by Lt. Gen. James Longstreet on the Union's left flank caused army commander Maj. Gen. George G. Meade to order Williams to transfer his entire corps to reinforce the left, in the vicinity of Little Round Top. Williams convinced Meade of the importance of Culp's Hill and managed to retain one brigade, under Greene, in their defensive positions. In an heroic defense, Greene and his brigade withstood the assault of Maj. Gen. Edward "Allegheny" Johnson's Confederate division (the "Stonewall Division") throughout the night, until the remaining brigades of the XII Corps returned. Early on July 3, Williams launched an attack against the Confederates who had occupied some of the entrenchments on the hill and, after a seven-hour battle, regained his original line. Unfortunately for Williams, General Slocum was late in writing his official report of the battle, and Meade submitted his report for the army without acknowledging the critical contributions that Williams and XII Corps made to the Union defense. In September 1863, the Union army in Tennessee was defeated at the Battle of Chickamauga and two corps were sent west to help them as they were besieged in Chattanooga—the XI and XII Corps. (They later were combined due to their small sizes into a new XX Corps, Army of the Cumberland.) Williams' division did not reach Chattanooga, but guarded railroads in eastern Tennessee. However, it did join Maj. Gen. William T. Sherman as part of XX Corps in the Atlanta Campaign and fought with distinction in a number of battles, particularly the Battle of Resaca. Williams was wounded in the arm at the Battle of New Hope Church on May 26, 1864. His division followed Sherman through his March to the Sea and the Carolinas Campaign. In these campaigns Williams lead XX Corps until, following the Battle of Bentonville, Joseph A. Mower was given command. Williams resumed leading his division. During this period, Williams received a brevet promotion to major general on January 12, 1865. Williams held the distinction of being the longest-serving division commander in the Union army, having led his division continually from March 13, 1862 until the end of the war barring temporary absences and corps command. He led his division in the Grand Review of the Armies in Washington D.C. in May 1865. Despite his seniority and long record of dependable service over three years, Williams was inexplicably never