"The evil commenced when we were in our Colonial state, but acts were passed by our Colonial Legislature, prohibiting the importation, of more slaves, into the Colony. These were rejected by the Crown."To the dismay of states' rights proponents, he was willing to accept the federal government's financial assistance to emancipate and transport freed slaves to other countries. At the convention, Monroe made his final public statement on slavery, proposing that Virginia emancipate and deport its bondsmen with "the aid of the Union".[140]
When Monroe was Governor of Virginia in 1800, hundreds of slaves from Virginia planned to kidnap him, take Richmond, and negotiate for their freedom. Gabriel's slave conspiracy was discovered.[141] Monroe called out the militia; the slave patrols soon captured some slaves accused of involvement. Sidbury says some trials had a few measures to prevent abuses, such as an appointed attorney, but they were "hardly 'fair'". Slave codes prevented slaves from being treated like whites, and they were given quick trials without a jury.[142] Monroe influenced the Executive Council to pardon and sell some slaves instead of hanging them.[143] Historians say the Virginia courts executed between 26 and 35 slaves. 