Could Congress have ended slavery without the 13th Amendment?

Question

The 13th Amendment to the United States Constitution reads:

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.

Without this or subsequent amendments, and with a 19th century understanding/interpretation of the Constitution and first 12 amendments, did the federal government have the power to end slavery?

Related question on the History StackExchange: https://history.stackexchange.com/questions/51511/what-was-the-south-actually-afraid-lincoln-or-congress-would-do-that-precipitate

Answer 1

Since the US Federal government didn't try to pass any such law (nor would it have been politically possible in the period shortly before the US Civil War), there is no way to know with assurance how such a hypothetical law would have been addressed by the Supreme Court of the day, nor by the various states.

Congress legally could have prohibited the importation of slaves after 1808, the constitution specifically grants this power.

Congress legally could have prohibited interstate commerce in slaves.

Congress could have repealed the Fugitive Slave Act.

Congress legally could have imposed heavy taxes on the ownership of slaves. If heavy enough these could have been a de facto abolition.

A series of Presidents could have appointed Justices inclined to overturn the Dred Scott decision (denying the possibility of citizen ship for most Negros, and denying that a "free" state could free slaves temporarily resident there).

Congress could have passed laws requiring negro votes to be counted in federal elections.

Various of the above hypothetical measures might have made slavery less economic, and thus less common, in time. Note that it is not likely that any actual Congress would have passed most of them.

But I do not see how, absent a constitutional amendment, and absent a war, a simple Federal statute could have constitutionally abolished slavery de jure throughout the US. Lincoln's Emancipation Proclamation was legally justified as a war measure, a confiscation from those in rebellion. It did not affect loyal slave states, such as Maryland. And it was never seriously tested in court anyway.

Answer 2

The answer of @DavidSiegel is generally correct, in my opinion, as far as it goes. I would add a few observations:

• Many state governments in the North abolished slavery by statute prior to the passage of the 13th Amendment (before and after the U.S. Civil War), as did many common law countries other than the U.S. But, U.S. states and most national parliaments have plenary legislative power, unlike Congress which has only limited legislative power as defined mostly in Article I of the U.S. Constitution.

• In places that abolished slavery by statute, they usually compensated former slave holders in eminent domain-like allowances. The argument that emancipation funded by tax dollars eminent domain style was constitutional spending for the general welfare would be stronger than the interstate commerce clause argument in the pre-1865 U.S. (the 13th Amendment was adopted in 1865).

• Congress also barred slavery prospectively in a number of territories and new states admitted to the Union prior to the passage of the 13th Amendment.

• Congress arguably could have banned interstate trade in goods produced with slave labor. This would have basically put most tobacco and cotton plantations, and the Southern textile industry to the extent that the South did not just export raw cotton, out of business. But, it also might have caused slave owners to kill many or most of their slaves to cut their expenses since the owners could no longer generate meaningful export income with their labor, something that probably would have been permitted by the Southern states at that time. (The heavy taxation of slave ownership could have posed similar dilemmas.)

• Because the Emancipation Proclamation was justified under the war powers of the federal government, emancipation in the U.S. was much less expensive in terms of public expenditures than it had been in countries and states that abolished slavery entirely by statute.

Congress legally could have imposed heavy taxes on the ownership of slaves.

This would have been a close call under the constitutional law of the power of Congress to tax at the time (pre-income taxation). It would have to be found to be an excise tax rather than an income tax and that wouldn't be an obvious conclusion and could come down to details of the statute imposing the tax.