He was appointed chief justice of New York in 1720 by Burnet, Hunter's successor, and continued as such through Burnet's and Montgomerie's administrations. Montgomerie died in 1731, and after his death and until the arrival of Cosby, in 1732, Morris acted as Governor of New Jersey, still retaining his position of chief justice in New York. On the accession of Cosby Morris' relations to the government changed and he was suspended from his office as chief justice by Cosby after having served as such for twenty years. The immediate cause of his suspension was his opposition to the views of his associate judges in relation to the jurisdiction of the Supreme Court in equity cases. Cosby and Ri]i Van Dam had a controversy before the Supreme Court involving their respective rights to the remuneration received by the latter as acting Governor during the period which elapsed between the death of Montgomerie and the arrival of Cosby. ^Morris decided in favor of Van Dam. Cosby was much displeased with the opinion, and on the Governor demanding a copy of it, Morris had it printed and sent to him with a letter which was decidedly discourteous to the Governor. Cosby removed him in 1733 and ai)pointed James De Lancey as his successor. This De Lancey was the father of De Lancey of De Lanccy's Mills, at West Farms. For note as to De Lancey family see supra.

His removal, however, made him more popular with the people. The county elected him at once to the Assembly, and the borough of Westchester elected his son Lewis. On his visiting New York salutes were fired in his honor, and deputations of citizens met and conducted him with loud acclamations to a public and splendid entertainment. Cosby's administration was so distasteful to his opponents that, in 1734, they determined to lay their grievances before the crown, and IMorris was selected as the messenger to go to England for that purpose.