Complex sentence: Cotton devoted his life to the construction of irrigation and navigation canals throughout the British Empire in India, however, his dream was only partially realized, but he is still honored in parts of rural Andhra Pradesh for his efforts.
Split into simpler sentences: Cotton devoted his life to the construction of irrigation and navigation canals throughout the British Empire in India. Unfortunately, his dream was only partially realized but he is still honored in parts of rural Andhra Pradesh for his efforts.