Final answer:
The divide over slavery in Missouri during the crisis of 1820 was attributed to a disagreement between northern opponents of slavery expansion and southern slaveholders, leading to opposition in the House and favor in the Senate.
Step-by-step explanation:
According to Lincoln’s Peoria speech, the divide over slavery in Missouri during the crisis of 1820 was primarily due to differences between the positions of southern slaveholders and northern opponents of the spread of slavery, which is represented by option B, 'The House of Representatives opposed it, the Senate favored it.' This crisis marked one of the earliest signs of a growing sectional storm as the United States grappled with the issue of whether new territories acquired from expansion should allow slavery. The Missouri Compromise was eventually negotiated to temper the divide, admitting Missouri as a slave state and Maine as a free state, and setting a precedent for the future states. However, the debate over slavery would continue to escalate, with pivotal moments such as the Kansas-Nebraska Act and the Dred Scott decision, further deepening national divisions over the issue.