Kansas-Nebraska Act of 1854 organized the northern Great Plains into the
territories of Kansas and Nebraska. It also repealed the Missouri Compromise
of 1820, which had prohibited slavery's expansion into the territories northwest
of the border between the states of Arkansas and Missouri. Under the terms of
the act, the residents of the Kansas and Nebraska territories would decide for
themselves whether they would enter the Union as free or slave soil states. By
repealing the Missouri Compromise, the Kansas-Nebraska Act reopened the
divisive issue of slavery's expansion and brought the United States closer to
civil war.
After the passing of the Compromise of 1850, which settled the slavery issue in
New Mexico and Utah, many Americans hoped that further controversy over
slavery would be avoided. But it soon arose again, largely because of plans for
building a transcontinental railroad to the Pacific coast. Because the settlement
of the western territories depended upon the construction of a
transcontinental railroad, the railroad's location took on tremendous
importance. Naturally, northern congressmen advocated a northern route,
while southern congressmen supported a southern route. The sectional debate
over the railroad's path threatened to block its construction, until Senator
Stephen A. Douglas of Illinois entered the fray. An ardent supporter of western
expansion and a tireless promoter of the Midwest's development, Douglas
understood that a transcontinental railroad was indispensable for that region's
political and economic future. Douglas also realized that if the transcontinental
railroad took a northern route, Chicago would most likely serve as its eastern
terminus. The resulting political and economic benefits that would accrue to
Douglas's home state of Illinois were obvious. But Douglas also had national
interests in mind. He genuinely believed that a populous and prosperous
Midwest would be able to mediate sectional conflicts between North and South,
and thus would promote sectional harmony and national unity.
Douglas recognized, however, that a transcontinental railroad running from
Chicago to San Francisco would be possible only after the settlement of the
vast midwestern lands between the Rocky Mountains and the Missouri River.
Douglas thus introduced a bill to organize the land into the territories of
Kansas and Nebraska, a move he believed would encourage settlers to migrate
into the northern Great Plains.
In his effort to secure support for the Kansas-Nebraska bill, Douglas found an
important ally in Missouri's influential senator, David R. Atchison, who was
seeking reelection in 1854. Atchison's reelection campaign pitted him against
Senator Thomas Hart Benton, a prominent opponent of slavery's westward
expansion. Unlike Benton, Atchison was a staunch supporter of slavery's
expansion, and he saw in the Kansas-Nebraska bill an opportunity to expand
slavery's domain. Atchison promised Douglas that he would support the
creation and settlement of the Kansas and Nebraska territories, but with one
critical condition. He insisted that the Missouri Compromise be repealed so
that his slaveholding constituents would be allowed to move into the new
Kansas and Nebraska territories with their human property.
In an effort to mollify Atchison's concerns, Douglas introduced a bill for the
territorial organization of Kansas and Nebraska, a bill that included a provision
that effectively repealed the Missouri Compromise. The bill asserted that the
Compromise of 1850 had superseded the 1820 principle that slavery would not
be extended north and west of the Arkansas-Missouri state border. The bill
also stated that the question of slavery in the territories should be settled by
the people living in them, an idea known as Popular Sovereignty.
This language conveniently favored Atchison in his senatorial campaign, for it
confronted his opponent, Thomas Hart Benton, with a difficult dilemma. If
Benton voted for the bill, he would betray his antislavery sympathies; but if he
voted against it, he would be defaulting on his promise to work for expansion
into Kansas and Nebraska. He voted against the bill and suffered defeat in the
race with Atchison. The final bill explicitly repealed the Missouri Compromise,
and the possibility of slavery in the new territories was made real.
The political ramifications of the enactment of the Kansas-Nebraska bill
reached deeply into the general political climate in which it was passed.
Support for it from southern members of Congress was nearly unanimous.
Northern Democrats were seriously split, half of their votes in the House going
for the measure and half against it. Nearly all northern Whigs opposed the bill.
This severe political division fractured the structure of the political party
system. The Whig Party was essentially destroyed in the South. The Democrats
were so seriously divided that their tenuous congressional majority became
highly vulnerable. A coalition of anti-Nebraska Democrats, northern Whigs,
Know-Nothings, and nativist groups joined the newly organized Republican
Party, making it a viable political force. By 1856 the Whigs had all but
disappeared, and the Republican Party was able to confront the weakened
Democrats with strong opposition.
In addition to these basic political changes, the Kansas-Nebraska Act had direct
ramifications. Kansas and Nebraska were promptly opened for settlement in
1854. Although Nebraska remained relatively quiet, Kansas, the destination of
most of the new settlers, became a political hotbed. Settlers came to Kansas
not only to develop the frontier but also—and perhaps more importantly—to
lend their weight in the determination of whether Kansas would be free or
Almost from the outset, political stability was lacking in Kansas. From the South,
proslavery Missourians traveled into Kansas to vote in favor of slavery, often
arriving in armed bands. Groups in the North and East, such as the Emigrant Aid
Company, helped so large a number of antislavery settlers move into the
territory that it was generally thought that an honest referendum of actual
settlers would not permit slavery in Kansas. But Missouri raiders entering the
territory in great numbers made an honest count impossible. In 1855 a
proslavery territorial legislature was established in the town of Lecompton,
Kansas, while at the same time an antislavery legislature was established in
Topeka. Almost inevitably, civil war erupted in Kansas as proslavery and
antislavery forces clashed for control of the territory. Although bloody, the
conflict remained inconclusive until the 1860s, when Kansas was finally
admitted to the Union as a free soil state.
The violence and political chaos in Kansas not only presaged the Civil War but
also helped to trigger it. In 1857 the proslavery territorial government in
Lecompton presented to Congress a constitution that would have incorporated
Kansas into the Union as a slave state. Chastened by the disastrous failure of
his Kansas-Nebraska Act, Stephen Douglas led congressional opposition to the
Lecompton constitution. Douglas and a diverse coalition of northern political
factions in Congress narrowly managed to defeat Kansas's proposed admission
to the Union as a slave state. The divisive battle over Lecompton, however,
shattered the unity of the national Democratic Party, which in 1860 would divide
into northern and southern wings. The collapse of the Democratic Party, the
one remaining national party, set the stage for southern secession in 1860.

Kansas-Nebraska Act
Visual Map of the Kansas, Nebraska Act