Massachusetts Senator Daniel Webster delivered his famous “Seventh of March” speech in 1850 to encourage the free and slave states to compromise over slavery. Webster traces the history of slavery back to the Constitutional Convention and the Northwest Ordinance of 1787, arguing that the founders believed that slavery would “gradually wear out and expire.” The founders supported an end to the international slave trade, gave Congress the power to limit the spread of slavery, and left the institution of slavery under the purview of the states. However, Webster noted, the cotton revolution and the expansion into new territories exacerbated tensions between the sections in the decades following the ratification of the Constitution. In addition, the rise of the abolitionist movement and proslavery ideologues furthered the divide between the free and the slave states. Compounding difficulties, some Northern state legislatures passed laws that refused to return fugitive slaves to Southern slaveholders, the latter of which Webster called a “constitutional obligation.” Finally, Webster issued a call for sectional compromise because believed that the “peaceable secession” of the Southern states was impossible and would make civil war inevitable.