After leaving Yale, he studied law under Charles Chauncey of New Haven (who later became a judge of the Superior Court).

In January 1786, at the age of 21, he was admitted to the bar of New Haven County and immediately set up his own practice, turning down an offer to be a tutor at Yale.

[2] While in his 20s, Daggett published and sold the "confession" of Joseph Mountain, an African American executed publicly before a crowd estimated at 10,000 in New Haven for rape.

[5] Daggett was admitted to the bar and entered into public life two years before the adoption of the Constitution of the United States.

[2] As well as holding a seat on the Council, he was appointed State's Attorney for the county of New Haven in June 1811, and continued in that office until he resigned it when chosen Senator in 1813.

[2] He was elected to the Senate as a Federalist to fill the vacancy caused by the resignation of Chauncey Goodrich and served from May 13, 1813, to March 3, 1819.

He was appointed to that office by a Legislature in which a decided majority was opposed to him in political principles and preferences, and yet the respect he had garnered as a public official and lawyer swayed their vote in his favor.

At the same meeting an anti-abolitionism resolution he also helped draft was passed: "The propagation of sentiments favorable to the immediate emancipation of slaves in disregard of the civil institutions of the States in which they belong, and as auxiliary thereto the contemporaneous founding of Colleges for educating colored people, is unwarrantable and dangerous interference with the internal concerns of other States, and ought to be discouraged.

Canterbury passed a bill stipulating that the selectmen of the town had to approve any out-of-state students of color seeking an education.

This meeting, held at the statehouse on September 9, 1835, found Noah Webster, Simeon Baldwin, and others helping to frame resolutions that condemned any interference by Congress with the treatment of slaves within any of the states, opposed the use of the mail for "transmission of incendiary information", proposed African colonization for "the free colored population", and "viewed with alarm the efforts of the abolitionists".

During this time, he served as chief justice of Connecticut's Supreme Court and as Yale's only full professor of law.