The people having determined that a convention be held to form a new constitution, Judge Ranney was chosen to represent the counties of Trumbull and Geauga. The convention was held in 1850. It was composed of the first men of the State; both parties seem to have vied with each other in sending their ablest representatives. There were William Medill, its President, who afterwards became Governor of the State; the venerable Ex-Governor Vance; Henry Stanbery, late Attorney General of the United States; Peter Hitchcock, for thirty years a judge of the Supreme Court; Benjamin Stanton, long a member of Congress; Judges Joseph E. Swan, Sherlock J. Andrews, Simeon Nash and William Kennon; Charles Reemelin, D. P. Leadbetter, William Sawyer, and others not less prominent in the Judicial and political annals of Ohio. In that convention, Rufus P. Ranney greatly distinguished himself. Although but thirty-six years of age he commanded the respect and admiration of all its members, and won for himself a high reputation as a sound lawyer and ready debater. No one was more looked to for advice, and none more generally correct in giving it. He was, in fact, a leader, whose council, in almost every instance, was acceded to by the convention. All the propositions which he introduced were for the welfare and benefit of the people. In the official report of the debates will be found his views upon nearly or quite all of the questions which agitated the convention. He was the champion of the people against monopolies, and many of the most important provisions in the constitution are the work of his hand. The course which he pursued met the hearty approval of the people and made his name prominent throughout the State. In response to the wishes of the members of the legal profession, and the general desire of the public, he was, by the legislature of 1851, chosen one of the judges of the Supreme Court. When the new constitution went into effect, he was elected to the same position by a large majority. Judge Ranney occupied a place upon the Supreme Bench until 1856, when he resigned on account of ill health. That year he was a member of the Cincinnati National Convention, which nominated James Buchanan for President. In March, 1857, Judge Ranney, unsolicited on his part, received from President Buchanan the appointment of United States Attorney for the Northern District of Ohio. This position he held until July, when he resigned. He then removed to Cleveland, where he resumed the practice of his profession, as a member of the firm of Ranney, Backus & Noble.