The Missouri Compromise of 1820, Compromise of 1850, and Kansas-Nebraska Act all dealt with the issue of slavery in the United States, and were attempts to address the growing tensions between free and slave states.
Here are some specific similarities:
All three were attempts to balance the interests of slave and free states. The Missouri Compromise, for example, established a line (36°30' north latitude) across the country, with slavery prohibited north of the line and allowed south of it. The Compromise of 1850 allowed for the admission of California as a free state, but also included provisions that favored slave states, such as the Fugitive Slave Act. The Kansas-Nebraska Act allowed for popular sovereignty (allowing settlers in the territories to decide whether or not to allow slavery) but repealed the Missouri Compromise line, which had previously been seen as a key boundary between free and slave states.
Each compromise was seen as a temporary solution to a long-term problem. None of the compromises fully resolved the issue of slavery, and tensions continued to mount between slave and free states. In fact, each of these compromises arguably made the situation worse, by inflaming tensions and polarizing public opinion.
All three compromises ultimately failed to prevent the outbreak of the Civil War. Despite the efforts of lawmakers to reach a compromise on the issue of slavery, the tensions between the North and South continued to grow, and eventually led to armed conflict in 1861.