Samuel Minter is listed in the 1860 Federal Census for London, Ohio. He was 40 years old in 1860, the year before his death. Note that a Jacob March (marble worker apprentice) and a Mark Hutchison (marble worker) are lodgers in the Minter household.
From The History of Madison County, Ohio (Chicago: W.H. Beers & Co., 1883):
The London Marble and Granite Works were established in London in the neighborhood of 1853 by Samuel Minter. Mr. Minter died in 1861, and the business was carried on for about one year by the present proprietor, Jacob March. The works were then purchased by Messrs. Hutchinson & Reitzell, who conducted the business together for a period when Mr. Hutchinson became sole proprietor. In June, 1866, Jacob March purchased a half-interest of Mr. Hutchinson, and the tow gentlemen operated together for about six months, when Levi March bought out Mr. Hutchinson’s interest, and the firm name became the March Brothers. Six months later, Mr. Jacob March became sole proprietor and carried on the business until 1872, when he sold to James Self. About this time, another marble shop was started in town by Aaron Bentezell. Mr. March became associated in the business as a partner with Mr. Bentezell. These gentlemen after about one year together dissolved, Mr. March purchasing. About the year 1875 Mr. March purchased the shop of Mr. Self and consolidated the two. The works were destroyed by the fire of 1874, but immediately thereafter rebuilt where now located on West High street, where can be found anything in the marble and granite line, for monuments or tombstones, and a full supply of limestone and freestone for door or window sills, doorsteps, etc.Nation Chapel Cemetery, Clark County, Ohio