You must not be aware of the fact that on the way to fight the first battle of the war, Bull Run (Manassas), that invading Union Brig. Gen. Irwin McDowell and his troops passed the slave pens in Washington, D. C., which held thousands of slaves.
Why did the Union Command not start there?
There are many records of this. Here is one.
The issue of slavery did not cause the war to begin. So, one must wonder what was the real cause.
actually yes the issue of owning slaves was one of the causes
and such an emotional cause it fanned many flames
You do point out the hypocrisy of many in the North. it does and still does exist
That doesn’t change that many more in the North and in the South knew owning slaves was wrong in every way possible.
If there hadn’t been nearly 4 million slaves primarily in the south there would not have been a Civil War
If only it wasn’t for all those pesky statements from southern leaders saying that they were rebelling over issues around slavery.
Slaves in DC was not a problem for the administration. General McDowell’s assigned objective was the Confederate army assembling near Manassas junction. Slavery was legal in the District of Columbia. Just as it was in Missouri, Kentucky, Maryland and Delaware.
The slave trade was illegal in DC.
The north didn’t start the war. The southern traitors did, and they started it for slavery.
The north fought the war to put down their insurrection.