1. The Missouri Compromise was a law passed by Congress in 1820 that allowed Missouri to enter the Union as a slave state and Maine to enter as a free state. Additionally, it established a line of latitude (the 36° 30' parallel) that would divide future states into either slave or free states. Any state north of the line would be free, while any state south of the line would be allowed to permit slavery.
2. The Compromise of 1850 was a law passed by Congress that settled several disputes between Northern and Southern states. It allowed California to enter the Union as a free state and organized territories of New Mexico and Utah with no mention of slavery. Additionally, it included a decision about slavery in Washington D.C. that permitted it but outlawed the slave trade within the district.
3. The Supreme Court ruling in the Dred Scott v. Sanford case was a decision made by Chief Justice Roger B. Taney in 1857 that stated slaves were not U.S. citizens and therefore had no right to bring a case to court. Additionally, the ruling declared that Congress could not prohibit slavery in any territory, effectively invalidating the Missouri Compromise and making slavery legal in all states.
4. The Battle of Antietam Creek was an important battle fought in 1862 during the Civil War. It was significant because it was the bloodiest single day of battle in American history, with over 22,000 casualties. The Union victory also led to Abraham Lincoln's Emancipation Proclamation, which declared that all slaves in Confederate-held territory were free. The Battle of Gettysburg, fought in 1863, was another important Union victory that marked a turning point in the war. It led to General Lee's retreat from Union territory and prevented the Confederacy from further invading the North. The Battle of Vicksburg, also in 1863, was an important Union victory that gave them control of the Mississippi River, splitting the Confederacy and allowing for more successful operations in the West.
5. The 13th, 14th, and 15th Amendments were all important additions to the U.S. Constitution that addressed issues of slavery, citizenship, and voting rights. The 13th Amendment, ratified in 1865, abolished slavery and involuntary servitude in America. The 14th Amendment, ratified in 1868, granted citizenship and equal protection under the law to all born or naturalized in the U.S. The 15th Amendment, ratified in 1870, prohibited the denial of voting rights based on race, color, or previous servitude. These amendments were significant in creating a more equal and just society for African Americans, and lays down the foundation for the Civil Rights Movement of the 20th century.