Such in outline was Jefferson's contribution to the colonization idea.
Its influence was unquestionably great: the "Notes on Virginia,"
privately circulated after 1781, and at length published in 1787, went
through eight editions before 1800, and must have been familiar to
nearly all of those concerned in the formation of the Colonization
Society.

Clearer still must the details of Jefferson's project have been in the
minds of the members of the Virginia Legislature in 1800, when, after
the outbreak of a dangerous slave conspiracy in Richmond, they met in
secret session to consult the common security. The resolution which they
reached shows unmistakably Jefferson's influence. With the delicate if
somewhat obscure periphrasis in which legislation concerning the Negro
was traditionally couched, they enacted: "That the Governor be requested
to correspond with the President of the United States on the subject of
purchasing lands without the limits of this State whither persons
obnoxious to the laws or dangerous to the peace of society may be
removed."[4] An interesting correspondence ensued between Monroe, who
was then Governor, and Jefferson. Both regarded the idea as something
far more important than a mere penal colony. Monroe, too, saw in it a
possible remedy for the evils of slavery, and refers to the matter as
"one of great delicacy and importance, involving in a peculiar degree
the future peace, tranquillity, and happiness" of the country. After
much discussion Africa was selected as the only appropriate site, and
approved by another Act of the Legislature. Jefferson lost no time in
attempting to secure land for the colony, but his efforts met with no
success. After a discouraging repulse from Sierra Leone, and the failure
of several half-hearted attempts to obtain a footing elsewhere, the
whole matter was allowed to sink into abeyance. For years a pall of
secrecy concealed the scheme from public knowledge.