After taking a preparatory course, Moore entered Union College in Schenectady, New York, in 1846, and graduated after a full course in 1850.
Edward Wootten of the Superior Court of Delaware, and in 1853 Moore opened a law office in Georgetown.
Upon Moore's retirement, Chief Justice Edward Gilpin said: "He has made a good officer and has tried more important capital cases than any other attorney general in the state; and during his term of office the law of murder has been firmly settled".
After his term as attorney general, Moore returned to his practice, giving much of his time to the affairs of the Junction and Breakwater and the Breakwater and Frankford Railroad Companies and the Old Dominion Steamship Company, whose local counsel he was.
He had frequently been troubled with this ailment and he had apprehended for years that some time, sooner or later, it would result fatally, but his death was wholly unexpected, as he had enjoyed excellent health up to that evening.