The best known, early American Baptist historian is Isaac Backus.  In the early 19th century he wrote “Church History of New England from 1620-1804” and some other notable books.
Prior to Backus, another man, planned to become a Baptist historian, but, while gathering materials, John Comer lived only thirty years, dying in 1734.  It is possible that both men knew each other, but whether that was true or not, their materials often overlapped.
In Comer’s diary we read that on May 25, 1723 the pastor of the Baptist church in Dartmouth, Philip Tabor, was imprisoned.  His crime was for refusing to pay the tax that was assessed by the town for the support of its Congregational minister.  The law was so unjust that when King George heard about it, it was he who ordered Tabor to be released.  And then on May 3, 1729, Brother Comer recorded the following: “A number of Baptists, Churchmen, and Quakers, in all 30 persons, belonging to the township of Rehoboth (Massachusetts) were committed to Bristol jail, by reason of their refusing to pay the minister’s rate.”  On this day, a week later he added, I went to visit the prison at Bristol with Mr. Stephen Gorton.  Upon the request of the prisoners I preached this day in the old prison at Bristol, from Psalm 86:11.  Sundry of the town attended the meeting.”  Psalm 86:11 reads: “Teach me thy way, O Lord; I will walk in thy truth; unite my heart to fear thy name.”
William Cathcart wrote in his Baptist Encyclopedia, “Mr. Comer was the most remarkable young man in the Baptist history of New England, and his early death was a calamity to be the churches in that section of the country, suffering at the time so severely from Puritan persecutions…”