History: American Old West, United States

• Dred Scott
The Dred Scott decision by the Supreme Court of the United States in 1857 declared the Missouri Compromise unconstitutional and that Congress had no authority to exclude slavery from the territories, thus opening these areas to slavery again depending on the local vote. Despite the efforts by presidents Franklin Pierce and James Buchanan to influence Kansas territorial governors to vote pro-slavery, Kansas voted to become a free state and the thirty-fourth state of the Union in 1861. The conflict also helped to foster the organization and development of the Republican Party in 1856, a mixture of free-soilers, expansionists, and federalists who opposed the extension of slavery into the Western territories. Abraham Lincoln, an early Republican, made clear his position on slavery in the famous Lincoln-Douglas debates which helped propel him to the presidency in 1860, "Never forget that we have before us this whole matter of the right or wrong of slavery in this Union, though the immediate question is as to its spreading out into new Territories and States". Lincoln branded slavery as a "monstrous injustice" and a "moral, social, and political evil". In 1862, Lincoln signed a law prohibiting the spread of slavery into all the remaining territorial possessions. During Lincoln's administration, two other important acts were passed which impacted the West—the Homestead Act and the Pacific Railroad Act.