What does "what hath god wrought"mean?
"Wrought" is an archaic past tense of the verb "work." It has also survived in the phrase "wrought iron," or ornamental ironwork.
Mr. Morse was quoting the Bible. His remark expressed amazement at the wonderful invention that God had allowed, or inspired, him to build: "humbling his own role while aggrandizing the invention," to quote this website, which also adds, "we more often quote it now with fear or horror than reverence."
Brush Up Your Bible: What Hath God Wrought!