The British gained momentum in the war when they turned their military efforts against the southern colonies. They scored repeated victories in the coastal towns, where they found legions of supporters, including slaves escaping bondage. As in other colonies, however, control of major seaports did not mean the British could control the interior. Fighting in the southern colonies devolved into a merciless civil war as the Revolution opened the floodgates of pent-up anger and resentment between frontier residents and those along the coastal regions. The southern campaign came to an end at Yorktown when Cornwallis surrendered to American forces.