Warning signals of the civil war that
would soon strike the United States were first seen in the
conflict that led to the Missouri Compromise of 1820. In
1819 the Missouri Territory was being considered for
admission into the United States. The problem arose when it
was suggested in Congress that slavery be restricted in
Missouri as a condition of admission.
At the time, there were an equal
number of slave states and free states in the Union. The
admission of Missouri, whether slave or free, would upset
the balance of power that existed between these rival
factions in the Senate. Under the terms of the Missouri
Compromise, however, both sides were temporarily appeased.
Maine, which was also requesting admission to the Union, was
granted entry as free state; Missouri was then admitted
without restrictions on slavery.
As the nation spread westward,
however, this question inevitably rose again. When it did,
it was in the context of the famous Supreme Court ruling in
the Dred Scott case of 1857. This decision declared the
Missouri Compromise unconstitutional and helped pave the way
for the Civil War.
In February 1819 the slavery issue
in the United States was dramatically brought to everyone's
attention. People were awakened to the gravity of the issue,
in the words of elder statesman Thomas Jefferson, "as though
a fire bell had rung in the night."
Before that time the public had
paid little attention to the slavery question. Then in 1819
a bill was presented in the House of Representatives that
would authorize Missouri to draw up a constitution for
statehood. Because slavery was already lawful in the
territory, many people took it for granted that Missouri
would enter the Union as a slave state. James Tallmadge of
New York, however, introduced an amendment to the bill. He
moved that no more slaves be brought into the new state. He
also moved that all children born of slaves in Missouri
after the state's admission should be free at the age of 25.
The representatives from the
Southern states were alarmed at these proposals. Free-state
members approved them. For three days the House excitedly
debated the question then passed the amendment by a vote of
87 to 76. The debate continued to rage throughout the
There were many reasons why the
struggle over the expansion of slave territory had not begun
earlier. The compromises that had been written into the
Constitution on the subject had satisfied the slave states.
The importation of slaves was authorized until 1808.
Congress was required to provide for the return of slaves
who escaped from one state to another. As far west as the
Mississippi River, a well-understood boundary line between
slave states and free states had been established. East of
the state of Ohio the boundary was Mason and Dixon's Line.
From Pennsylvania to the Mississippi River the boundary was
the Ohio River.
A balance had also been kept
between slave states and free states. There were then 11 of
each. Thus, in the United States Senate, where each state
had two members, the senators from slave and free states
were equal in number. This balance of power was useful to
the South. The Senate voted to reject the Tallmadge
amendment. Missouri continued to clamor for admission to the
Union. The future boundary between slave states and free
states in the Louisiana Purchase territory had to be
The next Congress agreed to a
compromise. Maine sought admission as a free state. Senator
Jesse B. Thomas of Illinois proposed that, with the
exception of Missouri, new slave states should not be made
out of the territory included in the Louisiana Purchase
north of 36o30' N. latitude, the contemplated southern
boundary of Missouri. The House and the Senate agreed to let
both Maine and Missouri enter the Union. Missouri would be a
slave state and Maine would be a free state. They also
agreed to accept for future guidance the dividing line that
Senator Thomas had proposed.
Some months later a supplementary
Missouri Compromise had to be made. The Missourians were for
the most part strongly pro-slavery. They had prepared a
constitution that forbade the state legislature to pass a
law freeing slaves without the consent of their masters. The
state legislature had also passed a law prohibiting the
entrance of free black people into the state. The national
House promptly voted against the admission of Missouri under
this proposed constitution. Another compromise was arranged,
mainly through the efforts of Henry Clay.
Missouri was finally received into
the Union on the condition that its legislature pledge never
to ignore the rights of citizens of another state coming to
Missouri. Missouri became the 24th state on Aug. 10, 1821.
The 23rd state, Maine, had been admitted nearly five months
earlier on March 15.
These compromises temporarily
stopped the debate. After the Mexican War, however, the
addition of more territory to the west of the Louisiana
Purchase revived the issue of slavery expansion. In 1854 the
Kansas-Nebraska Act repealed the provision that new slave
states not be created north of 36o30'.