Just a few comments. An action by the president is "legal" subject to adjudication. It can be struck down by the courts if it doesn't pass constitutional or other muster. I think there were cases where slave owners took the US to court over the issues you raise. If someone is aware of these, that would be good info to bring to the discussion.On July 17, 1862, Congress responded to some of Lincoln's statutory concerns he had expressed in his letter to Browning by enacting the Second Confiscation Act. This act authorized the seizure of property and slaves of any person who assisted or engaged in rebellion against the United States and declared that all seized slaves were "forever free of their servitude, and not again held as slaves." However, all property and slave seizures were subject to judicial review.
Following Union setbacks during 1862, Lincoln, under pressure from his advisors, some military commanders, abolitionists, and radical congressmen, opted to change the Union's strategy to that of hard war which included the destruction of enemy property and the overthrow of the South's social institutions. The Administration reasoned that the protection of slavery is what led to the war and slavery helped prolong the war.
Using only his constitutional authority as Chief Executive, Lincoln issued a Preliminary Proclamation on September 22, 1862, warning that emancipation would be forthcoming to any state in rebellion that did not return to the Union by January 1, 1863. Unlike the Second Confiscation Act, all slaves, regardless of the loyalty of their owner, would be free. He further alluded to compensation for slaveowners within any loyal slave state which implimented immediate or gradual emancipation as law, and as an enticement to those loyal slaveowners in the rebellious states, compensation for loss of property and slaves if their state returned to the Union.
On January 1, 1863 Lincoln, invoking his War powers as Commander-in-Chief, issued the Emancipation Proclamation affecting the slaves of both loyal and disloyal owners in areas of rebellion with no mention of compensation for the freed slaves.
Hence, my question. Was the Emancipation Proclamation legal? If so, why? If not, please explain.
Lincoln did issue the EP as Commander in Chief. However, the Confiscation Act did provide him with authority that was applied in the EP. For example, the 100 days notice provided by Lincoln in the preliminary EP follows the Act's requirement in Sec 6 for 60 days notice:
SEC. 6. And be it further enacted, That if any person within any State or Territory of the United States, other than those named as aforesaid, after the passage of this act, being engaged in armed rebellion against the government of the United States, or aiding or abetting such rebellion, shall not, within sixty days after public warning and proclamation duly given and made by the President of the United States, cease to aid, countenance, and abet such rebellion, and return to his allegiance to the United States, all the estate and property, moneys, stocks, and credits of such person shall be liable to seizure as aforesaid, and it shall be the duty of the President to seize and use them as aforesaid or the proceeds thereof. And all sales, transfers, or conveyances, of any such property after the expiration of the said sixty days from the date of such warning and proclamation shall be null and void; and it shall be a sufficient bar to any suit brought by such person for the possession or the use of such property, or any of it, to allege and prove that he is one of the persons described in this section.And as you note, the Confiscation Act did authorize the president to seize slave property from those in "rebellion." So again, this is authority that was granted by Congress.
It is useful to note that the EP was not applicable to certain sections of Louisiana and Virginia. These areas were under federal control, and thus not "in rebellion." And it did not apply to the state of Tennessee at all. Thus, a small minority of people in "loyal areas" of the Confederacy were not (immediately) subject to the loss of slave property.
Interestingly, the EP provides a definition of people who are "in rebellion":
"That the executive will on the 1st day of January aforesaid, by proclamation, designate the States and parts of States, if any, in which the people thereof, respectively, shall then be in rebellion against the United States; and the fact that any State or the people thereof shall on that day be in good faith represented in the Congress of the United States by members chosen thereto at elections wherein a majority of the qualified voters of such States shall have participated shall, in the absence of strong countervailing testimony, be deemed conclusive evidence that such State and the people thereof are not then in rebellion against the United States."Thus, per the EP, any person whose state is not represented in Congress is, on the face of it, a rebel - in the absence of "strong countervailing testimony." (Meanwhile, the Second Confiscation Act, in Sec 9 says, And be it further enacted, That all slaves of persons who shall hereafter be engaged in rebellion against the government of the United States, or who shall in any way give aid or comfort thereto, escaping from such persons and taking refuge within the lines of the army...)
The point is that, the EP does seem explicitly provide the ability for individuals in "rebel" areas to provide testimony that they themselves are not in rebellion.
I am not a lawyer, so I myself can't say if the EP was "legal." From what I can tell, it does seem like it pass judicial muster, to use a term. I think the real problem would be in the execution of the EP: were there valid and appropriate processes in place so that a person could provide "testimony" that he wasn't a rebel, and so, could not have his (chattel) property taken? If those processes were not in place, that would be a problem, I think. The question is, did the courts ever deal with these issues, and, what was the outcome?