On March 4, 1861, Abraham Lincoln addressed his fellow citizens, as was the custom of presidents taking the oath of office. His main purpose was to allay the anxieties of the southern states that their property, peace, and personal security were endangered because a Republican administration was taking office. Thus, Lincoln reiterated his promise not to interfere with the institution of slavery. Indeed, he affirmed the rights of states to order and determine their own institutions. To do otherwise, he noted, would violate the U.S. Constitution. Furthermore, he vowed to enforce the federal Fugitive Slave Act, which stipulated that slaves escaping from southern masters be returned to their owners.