The Post-Revolutionary-War Depression
Slater Mill in Warwick, Rhode Island
Scholars have previously argued that Newport's fall from prominence was largely based on economic factors. Elaine Forman Crane blamed Newport's decline on the disruption in trade caused by the years that the city was occupied during the Revolution. She argued that the six year disruption in Newport's commercial economy, and the simultaneous rise of the abolitionist movement in New England and Britain, caused a financial crash that Newport merchants could not emerge from. Lynne Whithey also focused on economic factors in her comparative history of the fortunes of Newport and Providence. She situated Newport's economic troubles during the Revolution in a broader context, arguing that Newport's colonial economy was founded on a mercantile model that was not sustainable after the Industrial Revolution arrived in Rhode Island in the 1780's. Newport did not have the waterways to power looms, and as a result, Providence eclipsed Newport as the primary city in Rhode Island. 
Newport in DeclineIn some cases, the people who left Newport actually had sided with the Crown. Loyalists were especially numerous in Newport's Episcopalian community...who left Newport when the British evacuated in October 1779.
The effects of the war on Newport's Quakers were more subtle. The community initially seemed to rebound in the post-war period. The New England Yearly Meeting, traditionally held at the Great Friends Meeting House in Newport, was able to resume there in June 1782. The meeting was also rejuvenated by the return of many of the Friends who had left the meeting during the years of the city's occupation.
The Quakers had permanently renounced their posts in government in the years leading up to the war, and their forfeiture of political power, coupled with their refusal to openly support the patriot cause during the Revolution, meant they also now occupied a much lower rung within Newport's social hierarchy. Even after the Revolution, many Newport residents still continued to harbor ill will towards the Quaker community for their actions during the war. Newport's Quakers would never regain the same level of power or respect they had held before the Revolution. 
Like the rest of the groups in Newport, the Congregationalists also suffered in the post-war recession, though they seem to have fared somewhat better than many of the other religious groups did. The Second Congregational Church was deprived of the leadership of Ezra Stiles, who, despite a desire to resume his post, left his congregation in Newport after he was offered the Presidency of Yale College at the war's end.
The Jewish congregation was the group that was most dramatically affected by the war. Some of its members were Loyalists, while others were ardent Patriots, and this divide, coupled with the community's relatively small size, created a situation in which the choices of a few prominent members of the community affected the entire group. Aaron Lopez created a huge amount of business for colonial Newport, and his position was similarly respected within Touro Synagogue. When he left Newport in 1776, he took nearly seventy members of Newport's Jewish community with him, and settled them in Leicester, Massachusetts.  Several other prominent Jews including Benamin Meyer, Isaac Hart, Myer Polock, Moses Michael Hays, and Isaac Touro, the synagogue's hazzan, held Loyalist sympathies. These individuals left Newport when the British evacuated Newport, and this further fractured the small community. In the census of 1782, only six Jewish families, out of the original thirty, remained in Newport, and by 1809, only Moses Lopez remained in Newport.  It is not known exactly why, when they had a perfectly good synagogue to go back to in Newport, so many members of the Jewish community remained in Leicester even after the war ended, but this pattern does seem to fit with the actions of members of other religious groups whose behavior had provoked suspicion and hostility from the patriots during the war.
The Role of the Merchant Elite in Newport's Fortunes
The evidence from Ezra Stiles diary makes a powerful case that Newport's colonial culture of religious diversity created a hostile environment for those merchants who belonged to religious groups that were judged as disloyal to the American cause during the Revolution. It is likely that these tensions continued after the war ended, and the post-war experience of Newport's merchant class, coupled with the broader demographic evidence of the city's religious and social dissolution after the war, supports this conclusion. The majority of Newport's merchant elite did not return following the war, either because they were Loyalists or because they belonged to groups which had been branded as Loyalist. Most of the wealthiest merchants in Newport fell into one or both of these categories some were Loyalists, and most were either Episcopalian, Quaker, or Jewish. Altogether, only forty percent of Newport's colonial elite remained in the city by 1789. 
There were only two merchants who ranked at the top of Newport's tax list in both the pre-war and post-war years: William and Samuel Vernon. Both were Congregationalists and both had been ardent patriots during the war. The Vernons, and the less-wealthy merchants who remained, tried to restart the maritime economy after the war, but they met with little success.  Without the help of the strong network of established Jewish, Episcopalian, and Quaker merchants, the Vernons were unable to stop the city's decline. This removal of most of Newport's colonial merchant community ultimately created an economic domino effect to which even the Congregationalists were susceptible.
ConclusionWhen the events of the Revolutionary period are examined from the point of view of the people who experienced them, it becomes clear that economics were only part of the story. The city that emerged after the end of the war was radically changed, socially as well as economically. Newport would never regain its prominence as a center of intellectual and religious diversity. Ironically, though freedom of thought and religious practice became law across the new nation in 1781, Newport's own culture of pluralistic pride and religious toleration did not survive the American Revolution.
Many of the footnotes refer to: Ezra Stiles. The literary diary of Ezra Stiles,: Ed. under the authority of the corporation of Yale university (New York: C. Scribner's sons, 1901), 1:166.