The U.S. Constitution explicitly forbade the federal government from abolishing the importation of enslaved people for 20 years after its adoption. This is outlined in Article I, Section 9, which states that Congress could not prohibit the importation of such persons before 1808.
To clarify the options you provided:
- The Constitution did not explicitly forbid abolishing slavery based on race.
- It did include a provision that effectively encouraged the slave trade in new states for 20 years, but it does not match your exact wording.
- It did not explicitly forbid abolishing slavery for 30 years; the 20-year limit was the specific timeframe provided.
Thus, the most accurate answer from your options is encouraging slavery in new states for 20 years after its adoption, given that it refers to the protection of the slave trade for that period.