kept some negroes, both free and slave,
from coming into the state upon their own initiative without certificates
of freedom. From 1810 to 1820 the number of slaves in Illinois increased
from 168 to 917, Illinois being the only state north of Mason and Dixon's
line having an increase in the number of slaves during the decade,
although in the Territory of Missouri, during this time, the number
increased from about 3000 to over 10,200. At the same time the number of
free blacks in Illinois decreased from about 600 to some 450, while they
increased in Indiana from nearly 400 to over 1200. Of the slaves in
Illinois in 1820 precisely 500 were in the counties of Gallatin and
Randolph, the former being the center of the salt-making industry, and the
latter the seat of the early French settlement at Kaskaskia.(504)

Whether the anti-slavery clause of the Ordinance of 1787 freed the slaves
of the old French settlers was long a disputed question, and it is certain
that a strict construction of the Illinois Constitution of 1818 made
further importation of slaves illegal. Many slave-owners passed through
southern Illinois to Missouri, because the main road for emigration by
land to that territory crossed the Ohio River at Shawneetown. Many of the
slaves who produced the large increase in the number of slaves in Missouri
from 1810 to 1820 must have gone over this route. In 1820 more than
one-seventh of the population of Missouri was slave.(505) The people of
Illinois could not fail to see that they were losing a certain class of
emigrants--the prosperous slaveholders. The loss became greater as the
likelihood of Missouri's admittance as a slave state increased. As early
as 1820 there was a rumor of the formation of a party in Illinois to
introduce slavery into the state in a legal manner.(506) The next year an
editorial in a leading newspaper of Illinois said: "Will the admission of
slavery in a new state tend to increase its population?--is a question
which has been of late much discussed both within and without this state.
It has been contended that its admission would induce the emigration of
citizens of states as well where slavery was, as where it was not
tolerated--that while it would attract the attention of the wealthy
southern planter, it would not deter the industrious northern farmer." The
editor cites Ohio and Kentucky as proof against the above argument. In
1810 Ohio had a population, in round numbers, of 230,700 and Ken