Under Varnum's leadership legislation moved through Congress and passed both houses on March 2, 1807. The House and Senate agreed on a bill, approved on March 2, 1807, called "An Act to prohibit the importation of slaves into any port or place within the jurisdiction of the United States, from and after the first day of January, in the year of our Lord, One Thousand Eight Hundred and Eight." The measure also regulated the coastwise slave trade. President Thomas Jefferson signed the bill into law on March 2, 1807. Many in Congress believed the act would doom slavery in the South, but they were mistaken.