[1][2] When word arrived of the attack on Fort Sumter, Bragg was engaged in a case at Oshkosh, Wisconsin, where he was acting as defense counsel for a woman who had been accused of murder.

[3]: 445 In July, after General John Pope replaced McClellan in overall command of the Union Army, the Iron Brigade was assigned to participate in raids against Confederate infrastructure and logistics south of the Rappahannock.

Colonel Bragg, was detached from the brigade and sent on a rapid march to the North Anna River, where they discovered a large Confederate force was present on their flank.

[6]: 54 [note 1] The mission was ultimately successful as two miles of Virginia Central Railroad track were destroyed and the Union raiders returned safely to Falmouth.

[3]: 446  General Irvin McDowell, who commanded their Division, was convinced that the Confederates represented an inconsequential force, and ordered the brigades to proceed on their march toward Centreville.

[6]: 62 [note 4] When the Confederates opened up cannon fire, General John Gibbon ordered the Iron Brigade to engage the enemy and attempt to capture the artillery.

During this time, Bragg received his official promotion to colonel, effective March 10, 1863,[4][6]: 129  and was one of several officers invited to meet with President Abraham Lincoln.

[6]: 132  In the Battle of Chancellorsville, the Iron Brigade was charged with securing the creation of a pontoon bridge at Fitz Hughes Crossing on the Rappahannock, southeast of Fredericksburg.

However, after remaining in position for two days under enemy shelling, on May 2, I Corps and the Iron Brigade were recalled to cross back to the north side of the river and move west to reinforce Hooker at Chancellorsville.

[3]: 458 Colonel Bragg became seriously ill after Chancellorsville, possibly due to the poor weather conditions during the battle, combined with a wound he received from being kicked by Major John Hauser's horse.

On both days, his brigade had performed poorly, marching and firing in a disorganized manner, scattering in the face of Confederate skirmishers, and accidentally shooting at members of their own unit.

[1][6]: 263 [12]: 611 [note 21] On the night of May 7, V Corps was ordered to proceed southeast toward Spotsylvania Court House, as Grant attempted to maneuver his army in between Lee and the Confederate capitol, Richmond.

Arriving at Laurel Hill, northwest of Spotsylvania Court House, on the morning of May 8, they found a Confederate force had already reached the site and occupied strong defensive positions.

[6]: 285 [note 23] After days of skirmishing and shelling at the fortifications around Spotsylvania Court House, V Corps was again ordered to move to the south, continuing the maneuver toward Richmond.

[3]: 468  After more days of entrenched stalemate, on the evening of May 26, Grant again ordered the Union divisions to stealthily evacuate their lines and proceed south around the Confederate right flank.

[6]: 283 [16]: 650 [note 24] Colonel Bragg's account of the actions of the Pennsylvanian brigade during the Overland campaign can be found in the Official War Records, Series 1, Volume 36, Part 1, Item 141.

[12]: 636–639 On June 12, they made another sudden evacuation of their position and crossed the James River, engaging the Siege of Petersburg, and entrenching southeast of the city.

In the battle, the Iron Brigade was part of a general assault on the Confederate line, charging half a mile over open field toward the enemy.

On July 30, a Union sapper mine detonated explosives underneath the Confederate trench, resulting in a day of fighting in what's called the Battle of the Crater.

[6]: 302  On August 18, 1864, they were part of the successful Union raid, known as the Battle of Globe Tavern, to cut the Weldon Railroad and reduce the supply lines for the Petersburg defenders.

[21] Bragg campaigned vigorously for the Democratic ticket in the fall, though papers commented that he didn't seem to share the candidate's views on African American suffrage.

[23] In the hotly contested 1875 United States senate election in the Wisconsin Legislature, Bragg was the choice of the Democratic caucus, believed to be a potential compromise candidate for the fourteen Republicans who had pledged to prevent the re-election of Matthew H.

[25][26] In more local affairs, Bragg engaged in a years-long feud with Congressman Charles A. Eldredge, who had defeated him running on an anti-war platform in the 1862 congressional election.

In the days before attended the convention in September, Bragg was arrested and accused of a financial fraud deriving from a transaction with the Tremont House institution in Chicago.

The matter was resolved when Bragg had to leave the convention to attend his daughter's wedding—a former ally, Daniel H. Sumner, convinced a group of delegates to pick him as a compromise candidate on the 1,601st ballot.

Daniel Sumner was seeking renomination, Arthur Delaney was again a chief rival, with Judge Hiram W. Sawyer of Washington County also in the race.

[39] Bragg resumed his law practice in Fond du Lac, Wisconsin, but returned to public office in January 1888, when he was appointed United States Minister (Ambassador) to Mexico by President Grover Cleveland.

[42] This consideration likely influenced his decision to become involved in the famous Cunningham gerrymandering cases of 1892, in which he advocated against a challenge to the Democrats' 1891 redistricting law (1891 Wis. Act 482) before the Wisconsin Supreme Court.

[48] The schism would prove permanent for Bragg, who supported McKinley for re-election in 1900, as well as state Republicans, such as gubernatorial candidates Edward Scofield in 1898 and Robert M. La Follette in 1900.

[50]: 204  Their youngest daughter, Bertha, married George Percival Scriven, who would go on to become the first chairman of the National Advisory Committee for Aeronautics, the forerunner of NASA.