Waterman's judicial career began with election as a judge of Vermont's probate court, a position he held from 1896 to 1906.

[1] Waterman moved back to Jamaica in 1870, and, in 1872, he was elected to a two-year term as State's Attorney of Windham County.

[1] In 1886, Waterman relocated to Brattleboro, where he established a law firm in partnership with James Loren Martin and George B.

[4] Waterman developed a reputation as a skilled attorney of superior integrity, which resulted in his 1891 appointment as a special master to ascertain the facts in a highly publicized lawsuit involving the Vermont Copper Company.

[5] Later that year, Waterman received an appointment from the United States Attorney General to take testimony and ascertain the facts of American Civil War claims against the federal government from residents of several southern and border states, including Mississippi, Arkansas, and Missouri.

[2] In 1896, Waterman was elected judge of the probate court for Windham County's Marlboro District, and he remained on the bench until 1906.

[2] The railroad was foreclosed on, and Waterman completed the transaction, after which the new owners reorganized the company as the Central Vermont Railway.

[1] Though he was close to 70 years old, Waterman was a consensus choice among members of the Vermont General Assembly for one of the seats.

[2] In retirement, Waterman continued to reside in Brattleboro and declined frequent requests for his services, including invitations to carry out temporary assignments as a special master, referee, and mediator.