The first advertisement for the Black Ball Line, owned by Jeremiah Thompson and his partners, announced a bold new approach to packet line service between New York and Liverpool: regular departure dates, whether the holds were full or not. This innovation allowed merchants and traders to plan and ship on a reliable schedule. On January 5, 1818, the new ship James Monroe sailed out of New York harbor, inaugurating the Black Ball Line. The ship Courier had left Liverpool on New Year's Day.