Governor
Cranston had been deputy governor under his brother-in-law, Walter Clarke for the year beginning in May 1676, but the following year the "War Party" was put in power with Benedict Arnold elected as governor. In May 1678 Arnold was once again elected as governor of the colony, and Cranston again elected as deputy governor. In a few weeks, however, Arnold was dead, and William Coddington was elected as governor, with Cranston continuing as his deputy. The tax law was modified at this time, requiring the governor to give legal notice to every town before levying a tax. The population of the colony was deemed to be about 1000 to 1200 freemen able to bear arms. At the beginning of November 1678, Coddington had also died in office. On 4 November Conanicut Island was incorporated as a township and called Jamestown in honor of the Duke of York, who soon became king (as James II & VII.)
During a special session of the General Assembly held from 8 to 15 November, Cranston was elected governor of the colony, with James Barker elected as his deputy. The Charter and other papers were obtained from Mrs. Coddington and put into the custody of the new governor. Many of the agenda items during his administration dealt with financial issues, and several finance or taxation laws were passed or repealed. One of the first acts was to pass the first tax levy since the recent war. A rate of 300 pounds was assessed, broken down by town as follows: Newport, 136; Portsmouth, 68; New Shoreham (Block Island), 29; Jamestown, 29; Providence, 10; Warwick, 8; Kingston, 16 (reduced to 8); Greenwich, 2; and Westerly, 2. Never, in the history of the colony, had there been such a disproportionate share in taxation, and the numbers clearly show the relative degree to which the various towns had suffered as a result of the war.
In 1679 the Crown confirmed the jurisdiction of Rhode Island over the Narragansett country, within which were the recent settlements of Westerly, Kings Town, and Greenwich. A letter of thankful acknowledgment was sent to King Charles II, but also with a request that the area around Mount Hope be added to the colony. However, disputes with the Connecticut Colony had not ended, and in his final official act, Cranston sent a letter to the King dated 6 January 1679/80, concerning disputed lands in the Narragansett county still claimed by Connecticut.