Summoned to the new Confederate capital of Richmond, Virginia, Beauregard received a hero's welcome at the railroad stations along the route.
He was given command of the "Alexandria Line" of defenses against an impending Federal offensive that was being organized by Brig.
Gen. Irvin McDowell (one of Beauregard's West Point classmates) against the Confederate railroad junction at Manassas.
Beauregard devised strategies to concentrate the forces of (full) General Joseph E. Johnston from the Shenandoah Valley with his own, aiming not only to defend his position, but to initiate an offensive against McDowell and Washington.
Despite his seniority in rank, Johnston lacked familiarity with the terrain and ceded tactical planning of the impending battle to Beauregard as a professional courtesy.
President Davis considered many of Beauregard's plans to be impractical for an army as inexperienced as the Confederates could field in 1861; throughout the war, Davis and Beauregard would argue about Beauregard's tendencies to devise grand strategies based on formal military principles.
Davis believed he lacked a pragmatic grasp of logistics, intelligence, relative military strengths, and politics.

The First Battle of Bull Run (First Manassas) began early on July 21, 1861, with an element of surprise for both armies— both McDowell and Beauregard planned to envelop their opponent with an attack from their right flank.
McDowell struck first, crossing Bull Run and threatening Beauregard's left flank.
For a while, Beauregard persisted in moving his troops for an attack on his right flank (McDowell's left, toward Centreville), but Johnston urged him to travel with him to the threatened flank at Henry House Hill, which was weakly defended.
Seeing the strength of the Union attack at that point, Beauregard insisted that Johnston leave the area of immediate action and coordinate the overall battle from a position 1.5 miles (2.4 km) to the rear.
Beauregard rallied the troops, riding among the men, brandishing regimental colors, and giving inspirational speeches.
The Confederate line held.

As Johnston's final troops arrived from the Shenandoah Valley, the Confederates launched a counterattack that routed the Union Army, sending it streaming in disorder back toward Washington.
William C. Davis credits Johnston with the majority of the tactical decisions that led to the victory, judging that "Beauregard acted chiefly as a dime novel general, leading the charge of an individual regiment, riding along the line to cheer the troops, accepting the huzzas of the soldiers and complementing them in turn.
The closest he came to a major tactical decision was his fleeting intention to withdraw from the Henry Hill line when he briefly mistook the advance of Johnston's reinforcements for the arrival of fresh Union troops."
Nonetheless, Beauregard received the bulk of the acclaim from the press and general public.
On July 23, Johnston recommended to President Davis that Beauregard be promoted to full general.
Davis approved, and Beauregard's date of rank was established as the date of his victory, July 21.

After Bull Run, Beauregard advocated the use of a standardized battle flag other than the "Stars and Bars" Confederate national flag to avoid visual confusion with the U.S. flag.
He worked with Johnston and William Porcher Miles to create the Confederate Battle Flag.
Confederate women visiting Beauregard's army contributed silk material from their dresses to create the first three flags, for Beauregard, Johnston, and Earl Van Dorn; thus, the first flags contained more feminine pink than martial red.
However, the official battle flag had a red background with white stars.
Throughout his career, Beauregard worked to have the flag adopted, and he helped to make it the most popular symbol of the Confederacy.

As the Army went into winter quarters, Beauregard caused considerable friction with the Confederate high command.
He strongly advocated an invasion of Maryland to threaten the flank and rear of Washington.
With his plan rebuffed as impractical, he requested reas
Summoned to the new Confederate capital of Richmond, Virginia, Beauregard received a hero's welcome at the railroad stations along the route. He was given command of the "Alexandria Line" of defenses against an impending Federal offensive that was being organized by Brig. Gen. Irvin McDowell (one of Beauregard's West Point classmates) against the Confederate railroad junction at Manassas. Beauregard devised strategies to concentrate the forces of (full) General Joseph E. Johnston from the Shenandoah Valley with his own, aiming not only to defend his position, but to initiate an offensive against McDowell and Washington. Despite his seniority in rank, Johnston lacked familiarity with the terrain and ceded tactical planning of the impending battle to Beauregard as a professional courtesy. President Davis considered many of Beauregard's plans to be impractical for an army as inexperienced as the Confederates could field in 1861; throughout the war, Davis and Beauregard would argue about Beauregard's tendencies to devise grand strategies based on formal military principles. Davis believed he lacked a pragmatic grasp of logistics, intelligence, relative military strengths, and politics.
The First Battle of Bull Run (First Manassas) began early on July 21, 1861, with an element of surprise for both armies— both McDowell and Beauregard planned to envelop their opponent with an attack from their right flank. McDowell struck first, crossing Bull Run and threatening Beauregard's left flank. For a while, Beauregard persisted in moving his troops for an attack on his right flank (McDowell's left, toward Centreville), but Johnston urged him to travel with him to the threatened flank at Henry House Hill, which was weakly defended. Seeing the strength of the Union attack at that point, Beauregard insisted that Johnston leave the area of immediate action and coordinate the overall battle from a position 1.5 miles (2.4 km) to the rear. Beauregard rallied the troops, riding among the men, brandishing regimental colors, and giving inspirational speeches. The Confederate line held.
As Johnston's final troops arrived from the Shenandoah Valley, the Confederates launched a counterattack that routed the Union Army, sending it streaming in disorder back toward Washington. William C. Davis credits Johnston with the majority of the tactical decisions that led to the victory, judging that "Beauregard acted chiefly as a dime novel general, leading the charge of an individual regiment, riding along the line to cheer the troops, accepting the huzzas of the soldiers and complementing them in turn. The closest he came to a major tactical decision was his fleeting intention to withdraw from the Henry Hill line when he briefly mistook the advance of Johnston's reinforcements for the arrival of fresh Union troops." Nonetheless, Beauregard received the bulk of the acclaim from the press and general public. On July 23, Johnston recommended to President Davis that Beauregard be promoted to full general. Davis approved, and Beauregard's date of rank was established as the date of his victory, July 21.
After Bull Run, Beauregard advocated the use of a standardized battle flag other than the "Stars and Bars" Confederate national flag to avoid visual confusion with the U.S. flag. He worked with Johnston and William Porcher Miles to create the Confederate Battle Flag. Confederate women visiting Beauregard's army contributed silk material from their dresses to create the first three flags, for Beauregard, Johnston, and Earl Van Dorn; thus, the first flags contained more feminine pink than martial red. However, the official battle flag had a red background with white stars. Throughout his career, Beauregard worked to have the flag adopted, and he helped to make it the most popular symbol of the Confederacy.
As the Army went into winter quarters, Beauregard caused considerable friction with the Confederate high command. He strongly advocated an invasion of Maryland to threaten the flank and rear of Washington. With his plan rebuffed as impractical, he requested reas
P. G. T. Beauregard