Question: Which brigadier general was killed in a frontal assault launched by Union major General William T Sherman?

Context paragraphs:
Henry Goddard Thomas: Brigadier General and Brevet Major General Henry Goddard Thomas (April 5, 1837 – January 23, 1897) was a Union general in the American Civil War.  A native of Portland, Maine, Thomas graduated from Amherst College in 1858 and was admitted to the bar shortly thereafter.  He enlisted as a private in the 5th Maine Volunteer Infantry Regiment.  Promoted to captain in June 1861, Thomas was present at the First Battle of Bull Run and the Peninsula Campaign among other battles.  In February 1863, Thomas was appointed colonel of the 2nd United States Colored Infantry.  In December 1863, Thomas was appointed colonel of the 19th United States Colored Infantry.  On November 30, 1864, President Abraham Lincoln appointed Thomas a brigadier general of volunteers to rank from his appointment date.  The President nominated Thomas for the appointment on December 12, 1864 and the U.S. Senate confirmed the promotion on February 23, 1865.  Thomas was mustered out of the volunteers on January 15, 1866.  On March 29, 1867, President Andrew Johnson nominated Thomas for appointment to the grade of brevet major general of volunteers for his service during the war, to rank from March 13, 1865, and the U.S. Senate confirmed the award on April 5, 1867.  Henry Goddard Thomas died in January 23, 1897 in Oklahoma City Indian Territory (Oklahoma) and is interred at Evergreen Cemetery in Portland, Maine.

Meridian Expedition: The Meridian Expedition took place from February 3 to March 6, 1864 under the command of Major General William Tecumseh Sherman, in command of the Department of the Tennessee.  The columns were under the command of Brigadier General William Sooy Smith and Colonel James H. Coates.  The expedition was tasked to destroy a rebel cavalry commanded by Major General Nathan Bedford Forrest, maintain communications with Middle Tennessee and take men from the defense on the Mississippi River to the Atlanta Campaign.  To maintain communications, they were to protect the Mobile and Ohio Railroad.  The expedition ended with the Union Army abandoning Yazoo City.

John H. Kelly: John Herbert Kelly (March 31, 1840 – September 4, 1864) was, at the time of his promotion, the youngest brigadier general in the Confederate States Army.  He became one of the youngest generals to die during the American Civil War, at the age of 24.  His death occurred during an engagement at Franklin, Tennessee on September 2, 1864 during Major General Joseph Wheeler's raid into Tennessee in August and early September 1864 in an attempt to destroy the railroad that Union Army Major General William Tecumseh Sherman was using to supply his force from Chattanooga, Tennessee during the Atlanta Campaign.

Romney Expedition: The Romney Expedition was a military expedition of the Confederate States Army during the early part of the American Civil War.  It is named for Romney, West Virginia, which at the time was still in the state of Virginia.  The expedition was conducted in this locale from January 1 to January 24, 1862, as part of the preliminary actions of Stonewall Jackson's Valley Campaign.  Confederate forces under Major General Thomas J. "Stonewall" Jackson cleared Union forces under Major General Nathaniel Banks and Brigadier General William S. Rosecrans from the lower Shenandoah Valley and surrounding Allegheny ranges, and then successfully severed the Baltimore and Ohio Railroad and the Chesapeake and Ohio Canal.

Lee's Mill Earthworks: Lee's Mill Earthworks is a historic archaeological site located at Newport News, Virginia.  The earthworks formed part of the fortifications along the James River, which included fortifications at Fort Crafford, as well as, Dam No.1, and Wynne's Mill in Newport News Park.  On April 5, 1862, advance units of Union Brigadier General Erasmus D. Keyes' IV Corps, under the command of Union Brigadier General William Farrar Smith, encountered Confederate units commanded by Brigadier General Lafayette McLaws at Lee's Mill.  Heavy rains and massive earthen fortifications defending the river crossing stopped the Union troops from proceeding to Richmond.  Confederate Major General John B. Magruder's extensive defensives beginning at Lee's Mill and extending to Yorktown along the Warwick River caused the Union Army of the Potomac Commander Major General George B. McClellan to initiate a month-long siege of the Warwick-Yorktown Line which lasted until May 3, 1862 and contributed to the eventual failure of McClellan's campaign.

Brigadier general: Brigadier general (Brig. Gen.) is a senior rank in the armed forces.  It is the lowest ranking general officer in some countries, usually sitting between the ranks of colonel and major general.  When appointed to a field command, a brigadier general is typically in command of a brigade consisting of around 4,000 troops (four battalions).  In some countries a brigadier general is informally designated as a one-star general (OF-6).

Wilmot Gibbes de Saussure: Wilmot Gibbes de Saussure (July 23, 1822  – February 1, 1886) was a brigadier general in the South Carolina militia, who served along with the Confederate States Army in South Carolina at various times during the American Civil War.  As a colonel, he led his regiment in the occupation of Fort Moultrie and the bombardment of Fort Sumter at the beginning of the war.  He was appointed brigadier general as well as adjutant general and inspector general of South Carolina militia in 1862.  He commanded part of the Charleston defenses during the Union siege of the city in 1863.  He also led his men in opposition to Major General William T. Sherman's march through the Carolinas.

Charles Garrison Harker: Charles Garrison Harker (December 2, 1837 – June 27, 1864) was a brigadier general in the Union Army during the American Civil War.  He was killed in action at the Battle of Kennesaw Mountain in northern Georgia during the Atlanta Campaign.  Fort Harker in Kansas, an active garrison of the United States Army from 1866 to 1872, was named in his honor.

Kenner Garrard: Kenner Garrard (September 21, 1827 – May 15, 1879) was a brigadier general in the Union Army during the American Civil War.  A member of one of Ohio's most prominent military families, he performed well at the Battle of Gettysburg, and then led a cavalry division in the army of Major General William T. Sherman during the Atlanta Campaign.  He developed a reputation for personal bravery and was cited for gallantry at the Battle of Nashville as an infantry division commander.

Battle of Kennesaw Mountain: The Battle of Kennesaw Mountain was fought on June 27, 1864, during the Atlanta Campaign of the American Civil War.  It was the most significant frontal assault launched by Union Maj. Gen. William T. Sherman against the Confederate Army of Tennessee under Gen. Joseph E. Johnston, ending in a tactical defeat for the Union forces.  Strategically, however, the battle failed to deliver the result that the Confederacy desperately needed—namely a halt to Sherman's advance on Atlanta.

Supporting paragraphs: Charles Garrison Harker Battle of Kennesaw Mountain
Answer: Charles Garrison Harker