[2] In 1849, the Meigs family returned to the District of Columbia, but in October 1850 they moved to Rouses Point, New York, where John's father was engaged in building Fort Montgomery.

But at-large appointments needed the approval of Secretary of War John B. Floyd, a corrupt and venal politician who strongly disliked Montgomery Meigs.

[18] On July 21, 1861, John participated in the First Battle of Bull Run, a disastrous Union defeat just a few miles from the national capital.

Although John wished to return to his unit, his father ordered him to depart for West Point after reporting to General Scott.

Major Hunt later wrote: On the death of Lieutenant Craig, Cadet Meigs performed his duties until the close of action with spirit and intelligence, and was very useful, after the affair was over, in conveying orders, observing the enemy, and rallying our troops.

He wrote in his after-action report, "Meigs carried my orders promptly, and a braver and more gallant young man was never in service.

"[18] He also praised John in a letter to General Meigs, saying, the "gallant conduct of your son, and his exertions in carrying orders for me in the field" "recommended him to be immediately made a Lieut.

[17] In his defense, Miles claimed that Cadet Meigs had issued orders which he was not authorized to give, and that this was part of the cause of the disagreement between himself and Richardson on July 21.

[12] He engaged in extensive surveying of the area and drew hundreds of topographical maps,[32][33][34] and assisted in designing and overseeing the construction of defensive works.

[12] Meigs was made Chief Engineer of the Shenandoah Valley for the Department of West Virginia (a Union military district) on November 3, staying in the position until August 17, 1864.

Although the raid itself did little to disrupt Longstreet's supply lines, several cavalry corps of the Army of Northern Virginia fruitlessly searched for Averell's command for three months.

Grant resolved to strike at the Confederacy on multiple fronts, including a major attack from West Virginia southwest through the Shenandoah Valley.

Sigel was replaced as commander by Brigadier General (Volunteers) David Hunter, who resumed the offensive and pushed toward Staunton, Virginia.

[36] Meigs helped repair the bridge over Passage Creek (burned during Sigel's retreat) on May 15, which had temporarily stalled Hunter's advance.

Meigs also informed him that he had burned the home of a Virginian who had helped capture or kill some of Sigel's retreating troops two weeks earlier, and discussed a rumor that Southern women had armed themselves to fight for the Confederacy.

[38] As Hunter prepared to attack the village of Piedmont, Virginia, on June 5, Meigs suggested that cavalry be sent in a feint to take Mount Crawford overlooking the town.

[41] Lieutenant Colonel John Platner's 1st Regiment of New York Volunteer Veteran Cavalry briefly skirmished with the defenders on Mount Crawford.

[12] It is known that he reconnoitered the battlefield during the day, and was the one to inform Hunter that a gap in the center of the Confederate lines had only partially been filled by the 60th Virginia Infantry.

His army was delayed again in its crossing of the Big Otter River on June 16, as Meigs struggled for two hours to build yet another pontoon bridge.

[54] His supply lines long and under attack and supporting armies stymied in their attempt to reach him, Hunter retreated back to West Virginia.

[58] From Meigs, Sheridan learned that the long ridges in the Shenandoah were not the great protective barriers Union commanders had assumed.

[57] On August 17, John Rodgers Meigs was appointed Chief Engineer of the Middle Military Division and aide-de-camp to General Sheridan.

[12] After Hunter's retreat from the Shenandoah, Confederate Lieutenant General Jubal Early rushed north with his Army of the Valley up the Shenandoah, invaded Maryland, and threatened Washington, D.C. Sheridan was determined to wipe out Early's forces, but he needed to move cautiously so that no major defeat would occur that might imperil the re-election of President Abraham Lincoln in November.

What is known as the Valley Campaign opened on August 16 in the Battle of Guard Hill, when Union forces surprised Confederate cavalry riding to reinforce Early in Maryland.

Meigs and two assistants spent the day mapping the area around Harrisonburg, Virginia, plotting routes for the movement of Sheridan's troops.

As Meigs and his assistants rode at dusk along the old Swift Run Gap Road, which intersected Warm Springs Turnpike between Harrisonburg and Dayton, Virginia, (where Sheridan's headquarters were), they encountered three men in blue.

The men turned out to be Confederate scouts attached to a cavalry brigade commanded by Brigadier General Williams Carter Wickham.

[65][64] Realizing whom his men had killed, Wickham released his prisoner and sent him back to Sheridan in the hopes of telling a more accurate version of the story.

Local townspeople pleaded for them to stop, and Union soldiers often helped them carry belongings out of the house before setting fire to it.

[68] The high relief sculpture depicts a two-thirds life-size John Rodgers Meigs, in his first lieutenant's engineer uniform, lying on his back in the mud.