In 1853, Mr. Rice was elected a member of the common council, and a year later he was president of that body. In 1855, he received, from a large number of citizens of all parties, a flattering request that he would permit them to nominate him for the mayoralty of Boston. He reluctantly acceded to their request, and, after a sharply-contested campaign, was elected by a handsome majority. His administration of city affairs proved so satisfactory that he was re-elected, the following year, by an increased majority. By his wisdom, energy, and rare administrative ability, Mayor Rice gained a wide and enviable reputation. He was instrumental in accomplishing many reforms in municipal administration, among which were a thorough reorganization of the police; the consolidation of the boards of governors of the public institutions, by which much was gained in economy and efficiency; the amicable and judicious settlement of many claims and controversies requiring rare skill and sagacity in adjustment; and the initiation of some of the most important improvements undertaken since Boston became a city. Among these may be mentioned the laying out of Devonshire Street from Milk Street to Franklin Street, which he first recommended, as well as the opening of Winthrop Square and adjacent streets for business purposes, the approaches to which had previously been by narrow alleys. The magnificent improvements in the Back Bay, which territory had long been the field of intermittent and fruitless effort and controversy, were brought to successful negotiation during his municipal administration, and largely through the ability, energy, and fairness with which he espoused the great work. The public schools continued to hold prominence in his attention, and he gave to them all the encouragement which his office could command; while his active supervision of the various charitable and reformatory institutions was universally recognized and welcomed. The free city hospital was initiated, and the public library building completed during his administration.