1832 Frederick William Miles and Charlotte Mears were married in Boston, Massachusetts, in November. The New Brunswick Courier, on November 10, reported, "m. Boston Mass. by Rev. Malcolm, Rev. Frederick William Miles of this city / Miss Charlotte Mears d/o Elijah Mears, Boston." 
1837 Charlotte (Mears) Miles died on December 10 in Fredericton, York County, New Brunswick. The New Brunswick Courier, on December 16, reported, "d. Fredericton, York Co., Sunday morn., Charlotte Miles w/o Rev. Frederick W. Miles of that town."  Charlotte was buried at Old Burial Ground, Fredericton, York County, New Brunswick, Canada, Plot 3. Charlotte was born on May 20, 1813. 
1841 Frederick and Eliza's daughter Charlotte Mears Miles died on March 21. "d. Fredericton, York Co., 21st inst., Charlotte Mears MILES infant d/o Rev. F.W. MILES, age 11 mos." 
Frederick William Miles wrote his will six months prior to his death. He bequeathed to his daughter Elizabeth, when of age, five hundred pounds.
1842 Frederick William Miles died on February 2 in Fredericton, York County, New Brunswick. The New Brunswick Courier, on February 12, reported, "d. Fredericton, York County, 2nd inst., Rev. Frederick W. Miles, Minister Baptist Church, youngest s/o late Col. Elijah Miles, Maugerville, Sunbury County." 
Frederick William Miles was buried in the Old Loyalist Burying Ground, Section 3. Funeral preached by Ingrham Ebenezer Bill, contents published in a twenty page booklet in 1842.
A biography of Frederick William Miles is included in the Dictionary of Canadian Biography: 
Baptist minister and educator; born c. 1806 in Maugerville, N.B., elder son of Elijah Miles* and his second wife, Elizabeth Harding; m. first 29 Oct. 1832 Charlotte Mears in Boston, and they had a daughter who died young; m. secondly Eliza Billings, née Moore, of London, and they had one daughter; died 2 Feb. 1842 in Fredericton.
Elijah Miles was an adherent of the Church of England, but his second wife was a nonconformist, which might account for their two sons eventually espousing the Baptist faith. Frederick William Miles was educated at King's College in Windsor, N.S., graduating on 17 June 1824, and while there came under the influence of the Reverend David Nutter, a prominent Baptist preacher in the area. Miles was baptized into the Germain Street Baptist Church at Saint John in 1828 and on 7 September of that year was ordained its minister. During his two years as pastor, he received 50 members into the church.
In 1830 Miles left Saint John to study at the theological seminary in Newton, Mass., where he probably met his first wife, a native of Boston. He returned briefly to serve at his first charge before being called in 1833 or 1834 to the Fredericton Baptist Church. Miles's arrival in the New Brunswick capital coincided with a growing attack on the privileges of the Church of England, especially in education. In 1833 the established church dominated state-supported schools and its interests were staunchly protected by members of the Legislative Council, which in contrast to the elected House of Assembly was composed of crown appointees.
Miles and William Boyd Kinnear, a Fredericton lawyer and mha, are credited with first suggesting a Baptist seminary for New Brunswick. Their proposal was discussed and accepted at the annual meeting of the New Brunswick Baptist Association held in St George in July 1833, and both were included on a seven-member committee requested to draft a prospectus. In September a public meeting in Saint John formed the New-Brunswick Baptist Education Society and elected the Reverend Joseph Crandall* president and John McNeil Wilmot vice-president. The society chose Fredericton as the site for the seminary and upon completion of a building in December 1835 appointed Miles first principal. Charlotte Miles was placed in charge of the female students. Women were admitted on an equal basis with men, and "in this respect," according to scholar George Edward Levy, "the Baptist Seminary at Fredericton pioneered for all Canada." Admission was open to every denomination and no religious tests were required. In fact, non-Baptists formed the majority of the 70 pupils in the first class.
"The granting of provincial aid to this school seems to have set a kind of precedent for legislative aid to denominational schools other than Anglican," to cite a modern authority. In 1835 the assembly approved a grant of £500 for the seminary, but the Legislative Council withheld its approval, even though the petition for assistance was supported by "about six hundred respectable individuals belonging to the several religious denominations in this province." This pattern would be repeated a number of times in the next few years. A later petition had as many as 2,000 names. Finally, in 1840, a grant of £500 was approved, and by the mid 1840s the seminary was receiving an annual subvention.
A total of 109 male and 94 female students had entered the seminary by July 1838. Mrs Miles had died in December 1837 and the next year poor health forced her husband to give up his position temporarily to the Reverend Charles Tupper, father of Sir Charles. Miles was sent to England to try to recover his health and to find financial support for the school. Besides a special donation for a library, he collected £415. He also married Mrs. Billings, a widow with a small son. Unfortunately, his health failed to improve sufficiently and he had to resign the principalship six months after his return in October 1839. Miles continued to work for the New-Brunswick Baptist Education Society until his death at the age of 36 in February 1842. [Richard Wilbur. Sources: N.B., House of Assembly, Journal, 1842-46; Legislative Council, Journal, 1842-46. Columbian Centinel (Boston), 31 Oct. 1832. Royal Gazette (Fredericton), 15 April 1840. I. L. Hill, Old Burying Ground; Some loyalists and others (Fredericton, 1976). Newton Theological Institution, Historical catalogue (12th ed., Newton Centre, Mass., 1925). Bill, Fifty years with Baptist ministers. H. G. Davis, The history of the Brunswick Street United Baptist Church … (Fredericton, 1964). Levy, Baptists of Maritime prov. K. F. C. MacNaughton, The development of the theory and practice of education in New Brunswick, 1784-1900: a study in historical background, ed. A. G. Bailey (Fredericton, 1947), Saunders, Hist. of Baptists. A. A. Trites, "The New Brunswick Baptist Seminary, 1833-1895," Repent and believe: the Baptist experience in Maritime Canada, ed. B. M. Moody (Hantsport, N.S., 1980), 103-23.]
 Daniel F. Johnson, New Brunswick Vital Statistics from Newspapers, Volume 5, Number 510, November 10, 1832, New Brunswick Courier, Saint John, [NewBrunswickArchives].
 Daniel F. Johnson, New Brunswick Vital Statistics from Newspapers, Volume 7, Number 709, December 16, 1837, New Brunswick Courier, Saint John, [NewBrunswickArchives].
 Find A Grave Memorial 61335670, [FindAGrave].
 Daniel F. Johnson, New Brunswick Vital Statistics from Newspapers, Volume 9, Number 609, April 10, 1841, New Brunswick Courier, Saint John, [NewBrunswickArchives].
 Daniel F. Johnson, New Brunswick Vital Statistics from Newspapers, Volume 9 Number 1481, February 12, 1842, New Brunswick Courier, Saint John, [NewBrunswickArchives].
 Richard Wilbur, "Miles, Frederick William," Dictionary of Canadian Biography Online, Vol. 7 (University of Toronto/Université Laval, 1988), [CanadianBiographyOnline].