"The -people- preserved the Union."
No Walt .... The President of the United States unconstitutionally provoked and went to war to forcibly keep the Southern States from seceding. There was no referendum on whether the Northern States wanted to preserve the Union in 1861. Ft. Sumter was fired on and then Lincoln got what he wanted, the chance to subjugate the Southern States. Lincoln was acting in a self-serving capacity, he usurped his constitutionally mandated authority, and the Yankees went along for the ride. By 1865 Government-over-Man was the norm. That is NOT how the Founders set this counttry's government up.
Not needed. The Militia Act gives the president the discretion to act.
Of course Congress later voted funds to prosecute the war, and hundreds of thousands of loyal Union men volunteered to fight.
What about all those conscripted soldiers down south? Did they have a chance to vote on having their enlistments involuntarily extended?
Walt