The compromise would protect slavery in federal territories, current and future, south of the 36°30′ parallel. Congress would be forbidden from abolishing slavery in any state or interfering with the domestic slave trade. Congress would be forbidden from abolishing slavery in any state or interfering with the domestic slave trade. President-elect Lincoln refused to acquiesce to any extension of slavery into the territories, as he feared that the compromise would encourage Southern leaders to attempt to annex new territory South of the 36°30′ parallel in order to extend slavery.