The Army of Northeastern Virginia had marched from the environs of Washington to within just a couple of miles of General P. G. T. Beauregard's position behind Bull Run, but the 22-mile march had taken two and a half days. The green troops led by green commanders had marched so slowly that they had eaten all their rations and now McDowell was waiting for wagon trains to resupply them. The line had also strung out through the north Virginia countryside, and McDowell would have to wait another couple of days for all the stragglers to catch up.
Out in the Shenandoah Valley, Union General Robert Patterson had maneuvered himself completely out of the action, leaving General Joe Johnston free to take his army out of the valley and link up with Beauregard's army at Manassas. Johnston marched south, then took the Manassas Gap Railroad straight to Beauregard. Some of his troops were already arriving at Manassas Junction, but some would still be arriving as the battle was raging on July 21.
After yesterday's reconnaissance-in-force at Blackburn's Ford had been repulsed, McDowell was considering a flanking move around the Confederate left.
Also on this date, in western Virginia, Union General George McClellan issued a proclamation praising his army for their recent victories:
Headquarters army of Occupation, Western Virginia, Beverly, Va., July 19, 1861.
soldiers of the army of the West:
I am more than satisfied with you. You have annihilated two armies, commanded by educated and experienced soldiers, intrenched in mountain fastnesses and fortified at their leisure. You have taken five guns, twelve colors, fifteen hundred stand of arms, one thousand prisoners, including more than forty officers. One of the second commanders of the rebels is a prisoner, the other lost his life on the field of battle. You have killed more than two hundred and fifty of the enemy, who has lost all his baggage and camp equipage. All this has been accomplished with the loss of twenty brave men killed and sixty wounded on your part.
You have proved that Union men, fighting for the preservation of our Government, are more than a match for our misguided and erring brothers. More than this, you have shown mercy to the vanquished. You have made long and arduous marches, with insufficient food, frequently exposed to the inclemency of the weather. I have not hesitated to demand this of you, feeling that I could rely on your endurance, patriotism, and courage. In the future I may have still greater demands to make upon you, still greater sacrifices for you to offer. It shall be my care to provide for you to the extent of my ability; but I know now that, by your valor and endurance, you will accomplish all that is asked.
Soldiers! I have confidence in you, and I trust you have learned to confide in me. Remember that discipline and subordination are qualities of equal value with courage. I am proud to say that you have gained the highest reward that American troops can receive — the thanks of Congress and the applause of your fellow-citizens.
Geo. B. Mcclellan, Major-General.
Union General John Pope issued a proclamation to the inhabitants of northern Missouri:
St. Charles, Mo., July 19, 1861.
To the People of North Missouri:
By virtue of proper authority, I have assumed the command in North Missouri. I appear among you with force strong enough to maintain the authority of the Government, and too strong to be resisted by any means in your possession usual in warfare. Upon your own assurances that you would respect the laws of the United States and preserve peace, no troops have hitherto been sent into your section of the country. The occurrences of the last ten days have plainly exhibited that you lack either the power or the inclination to fulfil your pledges, and the Government, has, therefore, found it necessary to occupy North Missouri with a force large enough to compel obedience to the laws. So soon as it is made manifest that you will respect its authority and put down unlawful combinations against it, you will be relieved of the presence of the forces under my command, but not till then.
I, therefore, warn all persons taken in arms against the Federal authority, who attempt to commit depredation upon public or private property, or who molest unoffending and peaceful citizens, that they will be dealt with in the most summary manner, without awaiting civil process.
Jno. Pope, Brigadier.General U. S. A., Commanding.