A division commander early in the war, Lafayette McLaws proved capable but enough to warrant further advancement. He graduated from West Point in 1842, and served as a captain of infantry for almost 10 years before resigning his commission to join the South on March 23, 1861.

The Georgian's assignments included: major, Infantry (May 1861)
colonel, 10th Georgia (June 17, 1861)
brigadier general, CSA (September 25, 1861)
commanding 1st brigade, Department of the Peninsula (October 3 - November 10, 1861)
commanding 2nd Division, Department of the Peninsula (November 10, 1861 - April 12, 1862)
commanding division, Magruder's Command, Department of Northern Virginia (April 12 - July 1862)
major general, CSA (May 23, 1862)
commanding division, lst Corps, Army of Northern Virginia (July 1862 - September 9, 1863)
commanding division, Longstreet's Corps, Army of Tennessee (September 19 November 5, 1863)
commanding division, Department of East Tennessee November 5 - December 17, 1863)
commanding District of Georgia and 3rd Military District of South Carolina, Department of South Carolina, Georgia and Florida (May 25 - July 1864)
commanding division, same department (July 1864 - April 9, 1865)

He saw action during the Seven Days. He fought at Harpers Ferry, Antietam, Fredericksburg, Chancellorsville and Gettysburg. He took part in the Knoxville Campaign.

Longstreet became displeased with his cooperation and preparations for the assault at Fort Sanders and at Bean's Station. On December 17, 1863, he was relieved of command, and charges brought against him for the Fort Sanders incident. A court found him guilty of some charges on May 4, 1864, but Davis disapproved the findings on the 7th and ordered him back to duty with his division. He was sent to the Southern coast where he fought at Bentonville. Following the war he worked in insurance, as a tax collector and a postmaster.