The Constitution had not given to the Federal Government power to emancipate slaves. The proclamation did not purport to rest upon any constitutional power, but upon war powers solely. But war powers last only while war lasts, and when it comes to an end, all sorts of people have all sorts of opinions as to the validity of acts done under them.
Public opinion at the time was keenly alive to doubts regarding the President's powers in this particular. Congress was flooded with petitions calling for action to confirm and validate the proclamation, but the way was beset with difficulties. Should the Constitution be amended, or would an act of Congress suffice? If the Constitution should be amended, should it abolish slavery everywhere or only in the places designated by the President? Should loyal slave-owners be compensated, as Lincoln desired? What were the chances of getting such an amendment ratified by three fourths of the states? And for this purpose should the rebel states be counted as still in the Union? If so, the requisite number might not be obtained.
The first resolution offered in Congress for such an amendment of the Constitution was proposed in the House on the 14th of December, 1863, by Representative James F. Wilson of Iowa, in these words:
Section 1. Slavery being incompatible with a free government is forever prohibited in the United States; and involuntary servitude shall be permitted only as a punishment for crime.
Section 2. Congress shall have power to enforce the foregoing section by appropriate legislation.
On the 13th of January, 1864, Senator Henderson, of Missouri, offered a resolution to amend the Constitution by adding thereto the following article:
Slavery or involuntary servitude, except as a punishment for crime, shall not exist in the United States.
These resolutions were referred to the Judiciary Committees of the respective houses.
On the 10th of February, Trumbull reported the Henderson Resolution from the Committee on the Judiciary, with an amendment in the nature of a substitute in the following terms:
Article XIII
Section 1. Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States or any place subject to their jurisdiction.
Section 2. Congress shall have power to enforce this article by appropriate legislation.