Colonel Ellsworth's last letter to his parents.--We find in the New York Sun the following letter from the late Colonel Ellsworth, on the eve of his march to Alexandria written to his parents, the last one to them, and probably the last written communication to any one:
Camp Lincoln, Washington, May 23.
The regiment is ordered to move across the river to-night.--We have no means of knowing what reception we are to meet with. I am inclined to the opinion that our entrance to the city of Alexandria will be hotly contested, as I am just informed that a large force have arrived there to-day. Should this happen, my dear parents, it may be my lot to be injured in some manner. Whatever may happen, cherish the consolation that I was engaged in the performance of a sacred duty, and to-night, thinking over the probabilities of the morrow and the occurrences of the past, I am perfectly content to accept whatever my fortune may be, confident that He who noteth even the fall of a sparrow will have some purpose even in the fate of one like me. My darling and ever loved parents, good-bye. God bless, protect, and care for you.