William W . Mackall William Whann Mackall ( January 18 , 1817 – August 12 , 1891 ) was a Seminole Wars veteran , Mexican - American War veteran and Confederate States Army brigadier general during the American Civil War . He was a United States Army officer for 24 years before he resigned his commission in order to join the Confederate Army . After the Civil War , he was a farmer in Fairfax County , Virginia . Early life . William W . Mackall was born on January 18 , 1817 in Cecil County , Maryland . He graduated 8th of 50 cadets in the United States Military Academy class of 1837 . Mackall married the sister of later Confederate Brigadier General Gilbert Moxley Sorrel . After his graduation from West Point , Mackall was commissioned a second lieutenant of the U . S . Army ' s 1st Regiment of Artillery . He was promoted to first lieutenant on July 9 , 1838 . Mackall was ambushed and severely wounded at River Inlet , Florida on February 11 , 1839 during the Second Seminole War . He was regimental adjutant between January 20 , 1840 and August 31 , 1841 . Mackall was appointed brevet captain and brevet major for gallantry during the Mexican - American War where he fought in the battles of Monterey , Contreras , Churubusco and Chapultepec . He served as an assistant adjutant general during the war . Mackall was wounded in the arm at the Battle of Chapultepec on September 13 , 1847 . After the war , Mackall continued to serve as an assistant adjutant general on the frontier , in the U . S . Army ' s Eastern Division and Department of the Pacific . He held the position of assistant adjutant general in the Department of the Pacific on May 11 , 1861 when he declined promotion to lieutenant colonel and assistant adjutant general . Mackall resigned from the U . S . Army on July 3 , 1861 . American Civil War . William W . Mackall began his Confederate States Army service as a lieutenant colonel and assistant adjutant general on September 9 , 1861 and was assigned to the Confederate Department Number Two on September 15 , 1861 . He became assistant adjutant general on the staff of General Albert Sidney Johnston . Mackall was promoted to brigadier general on March 6 , 1862 , to rank from February 27 , 1862 , through the influence of General P . G . T . Beauregard . Mackall had become disillusioned with Johnston ' s performance and became a supporter of Beauregard . Mackall replaced Brigadier General John P . McCown as commander of Confederate defenses on Island Number Ten in the Mississippi River on March 15 , 1862 . Soon thereafter , on April 7 , 1862 , Mackall was taken prisoner when the Union Army under Major General John Pope captured the island at the Battle of Island Number Ten . Mackall was exchanged on August 15 , 1862 . He then held a staff position as commissary of subsistence in the Department of East Tennessee between November 5 , 1862 and December 8 , 1862 . Mackall was in command of the Confederate Department of the Gulf for six days in December 1862 . Until mid - April , he served in command of the western part of the district after Major General Simon Bolivar Buckner was assigned to command the district and to fortify the defenses of Mobile , Alabama . Between April 17 , 1863 and October 12 , 1863 , Mackall served in the Army of Tennessee as chief of staff to General Braxton Bragg , his classmate at West Point . Mackall was relieved at his own request after the Battle of Chickamauga . Then , he commanded a brigade in Major General John H . Forney ' s division in the Confederate Department of Mississippi and East Louisiana between October 16 , 1863 and January 26 , 1864 . Between January 26 , 1864 and August 24 , 1864 , Mackall served as chief of staff in the Army of Tennessee under General Joseph E . Johnston . Mackall declined to serve with the Army of Tennessee when General John Bell Hood replaced General Johnston . After the end of his service with the Army of Tennessee on August 24 , 1864 , Mackall was inactive at Macon , Georgia . He was in command of Confederate forces in south Georgia between March 23 , 1865 and April 20 , 1865 , when he was captured by Union troops at Macon , but he saw no active service during this time . No record of his parole has been found . Aftermath . Mackall speculated in real estate and owned several farms in Fairfax County , Virginia after the war . William W . Mackall died on August 12 , 1891 at " Langley , " one of his farms in Fairfax County . He is buried at Lewinsville Presbyterian Church Cemetery , McLean , Virginia , on the site of " Lewinsville , " another of his farms .