Why is the yangtze river important to the development of china

The Yangtze river was intricate in ushering in human colonization of china some of the first signs of human activity, have been dated as far as 2 million years, later on in history due to the difficulty of crossing the river it became a border to the cultures and tribes settling there although this fact also ushered in conflicts between the established kingdoms, a common capital of Chinese settlements most recently being the republic of China was Nanjing, which was a strategic location on the Yangtze river