Complex sentence: During the spring of 1640, the Connecticut Colony endured a crippling grain shortage, which caused many cattle to die of starvation; this became a matter of survival for the Connecticut Colony, but due to its prosperity, not for Springfield.
Split into simpler sentences: During the spring of 1640, the Connecticut Colony endured a crippling grain shortage, which caused many cattle to die of starvation. The grain shortage became a matter of survival for the Connecticut Colony, but due to its prosperity, not for Springfield.