In OTL, the compromise over slavery included the following, from Article 1, Sec. 9:
The migration or importation of such persons as any of the states now existing shall think proper to admit, shall not be prohibited by the Congress prior to the year one thousand eight hundred and eight, but a tax or duty may be imposed on such importation, not exceeding ten dollars for each person.
What if this clause wasn't added, the rest of the document remained as OTL, but the power of Congress to restrict or regulate "the migration or importation of... persons" was left alone entirely.
How might the Convention have agreed to this? And assuming the necessary states still ratify it, how long would a ban on slave importation take, assuming it still happens?Finally, how does this affect the history of the institution in America?
(And yes, I've seen threads similar to this, but I still thought I'd float it)