The origin of the name "Rhode Island" is uncertain and cannot be attributed to one source. In 1524, the Italian navigator Giovanni Verrazzano made the first verifiable visit to Rhode Island by a European adventurer. He was in the employ of the French king Francis 1 and several Italian promoters, and was searching for an all-water route through North America to China. After landfall at Cape Fear, North Carolina, about March 1, 1524, he proceeded up the coast to the present site of New York City to anchor in the Narrows, now spanned by the giant bridge that bears his name. From there, according to a letter written by Verrazzano dated July 8, 1524, he sailed in an easterly direction until he "discovered an Ilande in the form of a triangle, distant from the maine lande 3 leagues, about the bignesse of the Ilande of the Rodes" which he named Luisa after the Queen Mother of France. Verrazzano's letter describing his visit to Rhode Island was known in England for it had been printed in English long before the Pilgrims came to New England. This letter was printed in Italian in 1556 and in English in 1582, and again in 1600, so that it may be considered as easily accessible to the early settlers before they left England. Today, it is believed that Verrazzano was describing Block Island (named in 1614 by Dutch mariner Adriaen Block). According to a 1625 Dutch account printed in Ioannes de Laet's Nieuwe Wereldt, Captain Adriaen Block referred to Aquidneck Island as "een rodlich Eylande", meaning "an island of a reddish appearance", in reference to its red clay soil. The earliest recorded use of the name by the English colonists is in 1637, when Roger Williams wrote "at Aquednetick called by us Rode Island." in a letter to Massachusetts Bay Colony Deputy Governor John Winthrop. Rhode Island's first permanent settlement (Providence Plantations) had been established at Providence in 1636 by Roger Williams, a radical clergyman, and a small band of followers who had left the repressive atmosphere of the Massachusetts Bay Colony to seek freedom of worship. Other nonconformists followed Williams to the Narragansett Bay area and founded the towns of Portsmouth (1638), Newport (1639) and Warwick (1642). Because titles to these lands rested only on Indians deeds, neighboring colonies began to covet them. To meet this threat, Roger Williams journeyed to England and secured a parliamentary patent in March 1643-44, uniting the four towns into a single colony and confirming his fellow settlers' land claims. On March 13, 1644, Aquidneck Island was officially named: "Aquethneck shall be henceforth called the Ile of Rods or Rhod-Island." The name "Isle of Rodes" is found used in a legal document as late as 1646.The Parliamentary Patent of 1644 served adequately until the Stuart Restoration of 1660 made it wise to seek a royal charter. In 1663 the name "Colony of Rhode Island and Providence Plantations" was adopted in the Royal Charter granted by King Charles II of England. Roger Williams, in 1666, wrote: "Rode Island (in the Greek language) is an Ile of Roses." Here we have the murky origins of "Rhode Island".
Sources: Documentary History of Rhode Island, Volume Two, Chapin, Howard M., Preston and Rounds Co., Providence, Rhode Island, 1919. Rhode Island: A History, McLoughlin, William G., W. W. Norton & Company, New York, New York, 1986