Short answers, pulled from the story.
Ambrose Burnside (1824-1881) was a Union general in the American Civil War, three-time governor of Rhode Island, and U.S. Senator. He is best known for his disastrous defeat at the Battle of Fredericksburg in December 1862, and the Battle of the Crater at Petersburg in July 1864, as well as for the distinctive facial hair style that gave English the word "sideburns."
On the 13th of December, 1862, Burnside's Army of the Potomac launched costly frontal assaults against Confederate positions on Marye's Heights at Fredericksburg, Virginia. The attack was poorly coordinated and repulsed with heavy casualties, earning Burnside the nickname "Butcher of Fredericksburg" and leading to his removal from command on the 26th of January, 1863.
The Battle of the Crater, fought on the 30th of July, 1864, at Petersburg, Virginia, involved exploding a mine under Confederate fortifications at Elliot's Salient. The attack failed because General Meade ordered Burnside to replace his specially trained Black troops with untrained white troops at the last hour. The chosen division, under Brigadier General James H. Ledlie, entered the crater instead of going around it; Ledlie was found drinking in a bombproof shelter during the fighting. Burnside's forces suffered 3,800 casualties.
The word sideburns derives from the name of Ambrose Burnside. He wore a distinctive beard style with strips of hair connecting his ears to his mustache while leaving his chin clean-shaved. The style was originally called "burnsides" and the syllables were later reversed to produce "sideburns."
Before the war, Burnside invented the Burnside carbine and attempted to manufacture it commercially, but financial misfortune and a broken $100,000 government contract ruined him. After the war, he served three one-year terms as governor of Rhode Island starting in 1866, became the first president of the National Rifle Association in 1871, and served in the U.S. Senate from 1874 until his death in 1881.
Burnside arrested Ohio Congressman Clement L. Vallandigham on the basis of a speech Vallandigham gave at a public rally in Mount Vernon, Ohio, on the 1st of May, 1863, in which he denounced President Lincoln as a "tyrant." Burnside had dispatched agents to the rally to gather evidence and then charged Vallandigham with violating General Order No. 38. President Lincoln ultimately freed Vallandigham and sent him to Confederate lines, and ordered Burnside not to arrest civilians or close newspapers without White House permission.