Answer:
1- US Constitution (1787) --- counted slaves as three-fifths of a person for representation .
2- 1820 Missouri Compromise --- created the 36º 30' parallel as dividing line between slave and free states.
3- Compromise of 1850 --- stated California would be free, New Mexico and Utah could decide for themselves, US would forgive Texas' debt in exchange for land, and slave trading would cease in Washington DC.
4- Kansas-Nebraska Act (1854) --- stated Kansas would be slave, Nebraska free. However, Kansas chose to be free, upsetting the balance.
5- 1860 Crittenden Compromise --- was the last compromise before the Civil War and would have strengthened slavery. Lincoln opposed it.
Step-by-step explanation:
1- The Constitution of the United States is the supreme law of the United States of America. It was adopted on September 17, 1787, by a constitutional convention in Philadelphia, Pennsylvania, which consisted of delegates from the various states that formed the United States. One of its original provisions was the Three-Fifths Clause, by which every slave was counted as 3/5 of a free man regarding representation in Congress.
2- The Missouri Compromise was an agreement between slave supporters and abolitionists in Congress. The agreement was made to regulate slavery in the westernmost territories of the United States.
It established that slavery should be prohibited in all states north of the 36° 30' latitude, except Missouri and states east of Missouri. In states south of the latitude slavery could be allowed if the authorities and the free population so desired.
3- The Compromise of 1850 was a series of five laws regarding slavery and the boundaries of territories acquired during the Mexican-American War, that ended two years before. These laws balance the interest of the slave states in the South and the non-slave states. Due to these laws, California was admitted to the Union as a non-slave state, Texas received compensation for its claims to areas west of the Rio Grande, the New Mexico Territory was organized without express bans on slavery, slave trade was banned in the city of Washington, and the Fugitive Slave Act of 1850 was called for to require all citizens to help return fugitive slaves.
4- The Kansas-Nebraska Act was passed in the United States in 1854 while Franklin Pierce was president.
The law was promoted by Stephen A. Douglas and made sure that parts of Great Plains territory were organized into two new territories: Kansas and Nebraska. These areas were then opened to settlers, which led to both Kansas and Nebraska getting enough residents to be admitted as the states. In line with the principle of popular sovereignty, the law provided that the inhabitants of these territories could introduce slaveholding if the free population so desired. This thus broke with the Missouri Compromise of 1820, and in effect repealed this.
5- The Crittenden compromise was intended to add six additional articles to the Constitution. These amendments would expand the Missouri Compromise to ban slavery north of latitude 36° 30'. South of this line, which was to be extended to the Pacific, slavery should persist in all existing and future territories. But that would also have meant that in states like California, where slavery was prohibited at that time, slavery should be introduced immediately.