一、攻占南京的门户——皖南北伐军要进攻南京,就必须首先攻占皖南。当时的皖南没有今日这般发达的铁路、公路网,大军行动较为不便,仅仅只能沿长江进出南京。朱元璋当年就是从江北渡江,然后从皖南去攻打南京的。太平天国时期,太平军曾与湘军在皖南地区激烈地争夺了好几年。由 First, capture the gateway to Nanjing - Wannan Northern Expeditionary Army to attack Nanjing, we must first capture Wannan. At that time, there was no such railway, road network and army operation in southern Anhui that were so developed today. It was only inconvenient to move in and out of Nanjing along the Yangtze. Zhu Yuanzhang then crossed the river from Jiangbei, and then from southern Anhui to attack Nanjing. During the Taiping Rebellion, the Taipings had fiercely vied with the Hunan army in southern Anhui for several years. by