Despite their earlier failure to garner support for a large-scale non-importation movement, Boston merchants try again in August 1768. They vow not to import any goods from Britain after 1 January 1769. Once again, Bostonians seek out supporters in New York and Philadelphia. This time, however, Boston merchants stand firm and make it clear that they will boycott British goods whether merchants in these ports support them or not (they also threaten to suspend trade with non-participating towns). In late August, New York merchants agree to stop importing British goods after 1 November. Philadelphia merchants reluctantly join the movement in March 1769. Boston patriots, meanwhile, launch a concerted effort to stamp out remaining importers. Violators' names are printed on handbills and in newspapers for all of Boston to see.