If Henry Clay's early career was dodgy, it was nothing compared to his later maneuvers. He likely pulled off what is perhaps the greatest backroom deal in all of U.S. history during the Presidential election of 1824, securing for himself the position of Secretary of State by supporting John Quincy Adams for the presidency. This would cement Andrew Jackson as a bitter enemy for the rest of their lives. (Source )

Despite Clay being the chief architect behind the Missouri Compromise, the text itself was penned by Senator Jesse B. Thomas of Illinois. Um, thanks Jesse? (Source)

The borders set down in the Missouri Compromise would result in an odd quirk of U.S. history: Missouri, along with Tennessee, borders the greatest number of other states. Count 'em: Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas, Nebraska. (Source )

Despite being a sort of tagalong for the inclusion of Missouri into the Union, support for Maine's inclusion as a state went back to the American War for Independence. Though long a part of Massachusetts (as Maine county), the interests of the county went largely ignored in favor of more populous areas. Way to go, Pine Tree State. (Source)

The basis for the 36 Degree and Thirty Minute placement of the line separating slaves and free states was actually determined over fifty years prior to the Missouri Compromise. In 1763, Charles Mason and Jeremiah Dixon were commissioned to settle a border dispute between Pennsylvania and Delaware. Their surveying of the land resulted in the Mason-Dixon line, which has served as an unofficial divisor between the North and the South since its establishment. (Source)