At the age of eighteen he began teaching, at twenty five was common school visitor, and two years later was first Superintendent of Schools for Jefferson County.  In November, 1843, he removed to Monroe, [sic] County, Michigan, his school there being constituted a branch of the state university, and from 1845 to 1849, he held the office of State Superintendent of Public Instruction.  During his term of office he built the first Union school house in the state at Jonesville and organized the first public school in the upper Peninsula.  In 1853 he was elected principal of the Albion Seminary, being the first and only layman to hold the office, but in fifteen months he resigned having been again chosen Superintendent of Public Instruction.  At the expiration of the second term, in 1859, he engaged in the private banking business, but in 1860 he organized and took charge of the Commercial College, which in 1868, he removed to Detroit, and of which he retained the charge until 1883.  In March 1863, he was appointed by President Lincoln collector of internal revenue for the third district of Michigan and was later also made receiver of commutation moneys.  In 1848 Mr. Mayhew received the degree of M.A. from the New England University, and in 1876 that of L.L.D.

Dr. Mayhew was a strong member of the Methodist Episcopal church and also an ardent advocate of temperance.  He was married in 1838 to Miss Adelane Sterling of Adams, N.Y.  In later years he spent most of his time in literary work, being the author of several prominent commercial text books.  His death occurred from heart trouble and took place early in the morning of April 7, 1894.  His life work ended at the advanced age of 80 years.