Well, let's see, the Harper's Ferry and Norfolk Navy Yard installations were abandoned by their garrisons, not seized.
Somewhere I posted that Col. Thomas Jackson was sent by Virginia to take charge of Harper's Ferry. I erred -- that didn't happen until May 1st, when he was sent with a detachment by General Lee.
And Lincoln abandoned all the U.S. Army forts in the Indian territory about the same time, ordering their garrisons back East.
President Lincoln was pretty canny, wasn't he?
The commander of the Gosport Naval Yard ordered the ships there scuttled on April 19.
Prior to that, Virginians had sunk ships in the channel to block their exit.
I will ask you again what the federal government did between April 15 and April 19 -- to the people of Virginia.
To suggest that "oh well, la-da-de-dah, the federal troops abandoned these facilities," is just beyond ridiculous.
You didn't seem to have a clear grasp of the sequence of events, now you are trying to backpedal.
Walt