In 1855, he served as assistant to the Chief Engineer, and was doing so when the Civil War began.
On April 20, 1861, Wright took part in an attempt to destroy the Norfolk Navy Yard dry docks. He was captured by Confederate forces during the night time excursion, but was exchanged several days later and returned to Washington.
In May of 1861, he began the building of Fort Ellsworth and other defenses to the Capital.
At the battle of First Bull Run on July 21, 1861, Wright served as Chief Engineer of the 17th Infantry, Third Division under Samuel P. Heintzelmann. During that battle, which was to prove a rout to the Union forces, Heintzelmann wrote is his report that Wright performed his duties in an 'able and fearless manner'.
Wright was promoted on August 6, 1861 to Major of Volunteers and then to Brigadier General of Volunteers on September 14 of the same year.
After First Bull Run, he became Chief Engineer for the brilliantly successful Port Royal Expedition - September 19, 1861. This proved to be the greatest, most significant action to restore the Union in 1861. He commanded the 3rd Brigade, which occupied Fort Walker on November 7, 1861.
In the following February, Wright headed the expedition which seized Jacksonville, St. Augustine, and other points in Florida, then onto Morris Island, South Carolina.
June 16, 1862 saw him lead a division in the attack on Secessionville.
On August 19, 1862 Wright was given command of the Department of the Ohio. He worked with Generals Don Carlos Buell and William Rosencrans on their Kentucky and Tennessee campaigns. But it was to prove a mixed blessing as politics went against him and his tenure in the department came to an end on March 25, 1863.
May 18, 1863 saw him ordered back East where, on May 25, he was given command of the 1st Division of General 'Uncle John' Sedgwick's VI Corps, Army of the Potomac. His division marched for days, earning his men the nickname of "Wright's Walkers", to get to Gettysburg.
The Sixth Corps arrived at Gettysburg late in the afternoon of July 2, 1863 after marching over 30 hours to get to the fight. Wright's First Division was spread out along the area from the Taneytown Road to what is now known as Warren Avenue at Little Roundtop. Very near the end of the intersection where Wright Avenue meets Warren Avenue was the scene of the 20th Maine's brave standoff against all odds. Wright's division was held in reserve and did not directly participate in the battle. On July 5, as fresh troops, they were sent in direct pursuit of Lee's retreating army as he headed south back towards Virginia. In a letter Wright wrote to his beloved wife, Louisa on July 18, 1863 he mentions shadowing Lee's footsteps through Fairfield, Maryland and, having crossed the range at South Mountain, again skirmishing with the rebel forces near Antietam Creek.
On November 7, Wright's division met with Confederate troops at the Rappahanock Bridge in a small, yet decisive battle forcing the rebels back across the river. Indeed, he was sited for gallantry for his performance in this battle. His division subsequently took an important share of the action in the Mine Run Campaign.
On May 4, 1864, the VI Corps was thrown into the thick of the fighting during the Wilderness Campaign. Wright's division took part in all of the confrontations that comprised this battle.
With the VI Corps, Wright moved on to do battle at the Spotsylvania Court House where he was wounded for the first time, being badly bruised by flying shrapnel. May 9 was to become the saddest day in the history of the Corps as their beloved leader, 'Uncle John' Sedgwick was felled by a sniper's bullet. Sedgwick has made it known that should anything befall him, his wish was that Wright was to take over command of the VI Corps. His wishes were echoed by President Lincoln, who recognized that his friend had not been treated fairly during the Department of the Ohio rout. General Order # 199 began with the words 'By direction of the President...'. Wright was to carry his command of the most elite fighting corps of the Union Army until the end of the war.
The VI Corps was involved in some of the most horrendous fighting at the Bloody Angle on May 12, 1864. On this date, he was commissioned to Major General of Volunteers.
In July, the VI Corps, along with 2 other corps, were sent hurriedly to Washington, DC to defend the capital against an impending attack by Confederate forces led by Jubal Early. July 12 saw the Rebels repelled as they approached the very edge of the city.
During this battle, one of the most awkward and potentially disastrous moments of Wright's career took place as he invited President Lincoln to view the ensuing battle. Bullets flew and an army surgeon standing right next to the President fell, wounded. Hastily, Wright tried to talk Lincoln down off of the parapet and to safety. He finally managed to do so only after much effort, much to his relief !
The autumn of 1864 found the VI Corps fighting with Phil Sheridan in the Army of the Shenandoah during the Valley Campaign. In October, Wright was left in temporary command of the while Sheridan journeyed to Washington. On October 19, 1864 the Union army came under attack by the troops of Jubal Early in the fog-laden pre-dawn hours at Cedar Creek, VA. During this battle, Wright was wounded, the left side of his face torn, but he continued to lead his troops, directing them to regroup. He had already conceived of strategies to take the fight back to the Rebels and was preparing to implement them when Sheridan returned. He resumed command and, inspiring the battle-weary troops onwards, was able to retake the field using Wright's very plans.
The Battle of Cedar Creek proved to be the turning point in at least Wright's resolve to lead his troops in helping to bring the rebellion finally to an end.
March 13, 1865 saw Wright promoted to Breveted Major General of the USA.
On April 2, 1865, the VI Corps were the first to penetrate the Confederate works at Petersburg, and were chiefly instrumental in the capture of Ewell's corps at Sailor's (Sayler's) Creek on April 6.
Wright's troops were present at the Appomattox court house during the surrender by Lee to Grant. The VI Corps saluted as the defeated Southern commander returned to his troops with the news their war was over.
The return to Washington, DC for Wright and his men was on June 6, 1865 - days after the main triumphant promenade of the North's victorious warriors down Pennsylvania Avenue on May 24. Nonetheless, they paraded proudly down the same avenue to the admiration of those grateful citizens who had again gathered to welcome their boys home.
On November 23, 1865, Wright was promoted to Lt. Colonel of the Regular Army.
From July 20, 1865 until August 28, 1866, Wright headed the Department of Texas, again under the command of Phil Sheridan. It proved to be a lonely posting, and he subsequently returned to the east and to Washington.
On June 30, 1879, he was promoted to Brigadier General of the USA and became the Chief of Engineers. During his tenure he was involved in a great many engineering projects throughout the United States.
Wright was retired due to age on March 06, 1884.