etts and was admitted to the Union as a State.
It was further enacted that slavery should be forever prohibited from
all territory of the United States north of the parallel 36 degrees 30',
that is, north of the southern boundary of Missouri. It is this part of
the act which is known as the Missouri Compromise. It was accepted as
a permanent limitation of the institution of slavery. By this act Mason
and Dixon's Line was extended through the Louisiana Purchase. As the
western boundary was then defined, slavery could still be extended into
Arkansas and into a part of what is now Oklahoma, while a great empire
to the northwest was reserved for the formation of free States. Arkansas
became a slave State in 1836 and Michigan was admitted as a free State
in the following year.

With the admission of Arkansas and Michigan, thirteen slave States were
balanced by a like number of free States. The South still had Florida,
which would in time become a slave State. Against this single Territory
there was an immense region to the northwest, equal in area to all the
slave States combined, which, according to the Ordinance of 1787 and the
Missouri Compromise, had been consecrated to freedom. Foreseeing this
condition, a few Southern planters began a movement for the extension
of territory to the south and west immediately after the adoption of
the Missouri Compromise. When Arkansas was admitted in 1836, there was a
prospect of the immediate annexation of Texas as a slave State. This did
not take place until nine years later, but the propaganda, the object of
which was the extension of slave territory, could not be maintained by
those Who contended that slavery was a curse to the country. Virginia,
therefore, and other border slave States, as they became committed to
the policy of expansion, ceased to tolerate official public utterances
against slavery.

Three more or less clearly defined sections appear in the later
development of the crusade. These are the New England States, the Middle
States, and the States south of North Carolina and Tennessee. In New
England, few negroes were ever held as slaves, and the institution
disappeared during the first years of the Republic. The inhabitants had
little experience arising from actual contact with slavery. When slavery
disappeared from New England and before there had been developed in the
country at large a national feeling of responsibility for its continued
existence, interest in the s