Final answer:
Illinois Senator Stephen Douglas was responsible for splitting the Compromise of 1850 into separate bills, which facilitated the process of getting each part passed by forming different coalitions of support.
Step-by-step explanation:
The person responsible for splitting the Compromise of 1850 into separate bills was Illinois Senator Stephen Douglas. After the resignation of Henry Clay from leading the compromise effort, Douglas used a strategic approach to enact the Compromise by breaking it down into individual parts, which allowed for the gathering of support from different political and regional interests. By introducing separate bills, rather than trying to pass the Omnibus Bill as a whole, he managed to get each part passed, with varying coalitions of Whigs and Democrats, Northerners and Southerners supporting different sections of the legislation.