What did the Logan's attempt to do about the Wallace's mistreatment of colored families? What was the risk of doing so?

Mr. Jamison offers to back the credit of those who boycott the Wallace store and shop in Vicksburg. The Logan family attempt to rally other black families to join the boycott of the Wallace store. This would certainly get them in trouble with the whites in the town. There would be retribution from the Wallaces and other whites for any blacks that "overstepped" their bounds.