He was the son of Johann "George" Petefish and Margaret Ream.

He married Martha "Mattie" Louisa Marshall Paul on December 23, 1868 in Cass County, Illinois. They had six children: Abraham Ellsworth, Grace Margaret, Harrison Wallace, Estella Clara, George Ellis and Alma Olive (who died as a teenager). Martha passed away in 1882, so Aaron then married Lourena Liter two years later.

From a 1906 biography: “The entire life of Aaron W. Petefish has been spent either in Cass or Morgan County. He received his education in the subscription schools which were conducted in the log school-houses of that period, but at the age of twelve years abandoned his studies to assist his father in work upon the farm.

On August 9, 1862, he was mustered into the service of the United States as Corporal in Company E, One Hundred and First Illinois Volunteer Infantry, served through the Atlanta campaign, and October 29, 1864, was discharged on account of disabling wounds received at the battle of Peach Tree Creek, Ga., being then a Sergeant in the same company and regiment. After returning to the farm he was compelled to walk upon crutches for about a year.

He first purchased a farm of 100 acres located in Cass County, which he traded for his present homestead near Literberry, and where he has resided since 1871. He now owns 410 acres of fine land, on which he is engaged in general farming and stock-raising.

Mr. Petefish cast his first vote for Abraham Lincoln, and since that time has faithfully maintained the cause of the Republican party. He has filled various local offices, and for many years has been a member of the School Board. In religion he is connected with the Christian Church at Literberry.”

“Historical Encyclopedia of Illinois and History of Morgan County” Munsell Publishing Co, 1906