Asa fitted for college with Rev. Frederick W. Hotchkiss, the venerated pastor of the church of Say-Brook, and graduated at Yale, in the class of 1792. Of his scholarship while a member of college,, it is sufficient to say that he shared the highest honors of his class, with the Hon. Roger M. Sherman.

After he was graduated, he taught for a time in the academy of North Salem and also Norwalk, and continued to teach while in the practice of his profession.
He studied his profession with Hon. Tapping Reeve, of Litchfield, and was admitted to the bar in 1795, and settled in the practice of law at Newtown, Fairfield Co., Conn., and was repeatedly elected the representative of that town to the General Assembly of the state, and in 1817, was elected a member of the governor's council, comprising at that time twelve members. In 1818, he was elected judge of the superior court and court of errors, which office he held until his death.

In the autumn of 1824, he removed from Newtown to New Haven, where he opened a law school, but which, owing to his declining health, he was obliged to relinquish; and after two journeys to the Springs, and through the Canadas, he returned to New Haven where he died. His widow survived him nearly twenty-five years, and died at the residence of her son in Brooklyn. It has been remarked by Professor Silliman, "that he kept up, through life, in a remarkable degree, a fresh acquaintance with his collegiate studies," and by the Hon. Thomas Day, that "he possessed a vigorous and discriminating mind." He was attentive to business, and prompt in the performance of official duty.