Jeffrey was born on January 17, 1836, in Clarksville, Ohio. His father, James Jeffrey, of New England ancestry, was a native of Monmouth County, New Jersey, and as a young man had gone to the Ohio country, where he established a farm and married Angeline Robinson, whose father was one of the first settlers of Warren County.
Until he was seventeen years old Jeffrey remained with his parents, moving with them to Auglaize County, Ohio, where, in St. Mary's, he completed his high-school education.
Business seems to have had a strong attraction for him, and after leaving school Jeffrey entered a country store near his home and served as a clerk for four years. Then followed a year of several business experiences which carried him eventually, in 1858, to Columbus, Ohio. Here he entered the office of Rickly & Brother, private bankers, and for eight years served as bookkeeper, teller, and cashier, respectively. He forsook these banking activities, however, in 1866, to become manager of the firm of Rickly, Howell & Company, wholesale and retail carpet and furniture dealers of Cincinnati. Three years later he returned to Columbus and with F. C. Sessions reentered the banking business, founding what is now known as the Commercial National Bank.
About 1877, while walking along one of the business streets of Columbus, he chanced to notice displayed in an empty store window a crude model of a machine invented by Francis M. Lechner, to be used in coal mines. It was called a cutter bar and was designed to undercut coal seams. Seeing great possibilities in the device, Jeffrey proceeded to organize the Lechner Mining Machine Company for the purpose of manufacturing the machine.
In 1883 he sold his banking interest, and acquired the controlling interest in the Lechner Company. From that time on it enjoyed a healthy and rapid growth. Gradually the plant was extended and new mining machinery and mechanical handling equipment were added to its output, so that at Jeffrey's death it was the world's largest manufactory of coal-mining machinery, the plant covering thirty-five acres of ground. During this period, too, the company name was changed to the Jeffrey Manufacturing Company.
In 1900 Jeffrey retired as president but he served as chairman of the board of directors for the remainder of his life. In addition to his interest in the Jeffrey Company, he owned the Ohio Malleable Iron Company of Columbus, was a director in a number of Columbus banks, and took an active interest in the city's charitable institutions. Jeffrey died on August 27, 1928.
Jeffrey was President of the Lechner Mining Machine Company.
On October 2, 1866, Jeffrey married Celia C. Harris of Columbus, and at the time of his death was survived by three sons and two daughters.
