Before leaving Boston, Coggeshall and many other Hutchinson supporters signed the Portsmouth Compact in March 1638 agreeing to form a government based on the individual consent of the inhabitants.

Coggeshall was very active in civil affairs, but a rift in the leadership of the colony caused him and several other leaders to leave in 1639, moving to the south end of the island and establishing the town of Newport.

His tenure was very short due to his death later the same year, but during his administration many laws were established which became the basis for the colony and the future State of Rhode Island.

[2][3] In 1632, Coggeshall and his family joined the mass migration of English Puritans to New England, sailing on the Lyon, the same ship that carried Roger Williams the year before.

[6] In 1634, Coggeshall moved with his family to Boston where he and his wife were admitted to the church on 20 August,[4] and where they became the nextdoor neighbors of William and Anne Hutchinson.

[9] Many of Hutchinson's supporters were ordered out of the Massachusetts colony, but a group of them (including Coggeshall) signed what is called the Portsmouth Compact before leaving Boston, thus establishing a non-sectarian civil government with a Christian focus, upon the universal consent of the inhabitants.

[9] The group initially planned to settle in New Netherland, but they were persuaded by Roger Williams to purchase some land from the Indians on Narragansett Bay.

[8] The following year, a disagreement prompted Coddington and a few other leaders, including Coggeshall, to leave Portsmouth and begin a new settlement called Newport at the south end of the island.

[11] Rhode Island historian and Lieutenant Governor Samuel G. Arnold made this tribute to the digest of statutes enacted under Coggeshall in 1647: For simplicity of diction, unencumbered as it is by the superfluous verbiage that clothes our modern statutes in learned obscurity; for breadth of comprehension, embracing as it does the foundation of the whole body of law, on every subject, which has since been adopted; and for vigor and originality of thought and boldness of expression, as well as for the vast significance and the brilliant triumph of the principles it embodies, the Digest of 1647 presents a model of legislation which has never been surpassed.

[8] Their oldest child John was very active in colonial affairs over a period of three decades, serving as treasurer, commissioner, assistant, and deputy governor.