Cracks had already begun to form in his relationship with Howe when plans were developed for an expedition to the southern colonies, command of which went to Clinton. He asked Howe for specific officers to accompany him and authority that an independent commander might normally have, but Howe rebuffed him on all such requests. In January 1776, Clinton sailed south with a small fleet and 1,500 men to assess military opportunities in the Carolinas. During his absence his fears about the situation in Boston were realized when the Dorchester Heights were occupied and fortified by the rebels in early March, causing the British to evacuate Boston and retreat to Halifax, Nova Scotia.