James C. Clendenin was born in "Upper Canada", which existed between 1791 and 1841 in what is now Southern Ontario, Canada. His Canadian parents are Lydia (Summerfield) and John Clendenin. He married Ruth Catherine Greenman in Canada on January 24, 1844. James and his family arrived in Newberg Township, Cass County, MI, in time to be included in the 1860 US Census. According to his Civil War pension file, he enlisted as a Pvt., Company G, 13th Regiment Michigan Volunteers, December 23, 1861, Cass County, for three years, and was discharged for disability the 29th of October, 1862 at Nashville. His reported disability was, "Rheumatic".

James was a staunch supporter of the North and President Lincoln in the Civil War and like other Canadian citizens of the time came to the United States primarily to fight the Rebels. His strong support for the war is shown in the names of some of his nine children: Horace Nyram Frazier, Emeline Elizabeth, Lydia Ann Louisa,James Sheldon Lewis, Matilda Margaret Jane, Victoria Velma, Abraham Lincoln, William Rosencrans, and Ulysses Simpson Grant. After the death of his wife, Ruth Greenman, in 1871, he married two more times, to Eunice Lease, of Fabius Township, St. Joseph County, MI, December 7, 1874, in Will County, IL, and to Harriet E. (Bover) Casselman March 27, 1888, in Marcellus, MI. Eunice (Lease) and James C. Clendenin had one child, Carrie Melissa (Clendenin) Miller, making James the father of ten children total.

One child of Ruth Catherine (Greenman) and James C. Clendenin has been unaccounted for in this bio until recently: James Shelton Lewis Clendenin, who married Emma Elizabeth Armable May 1, 1879, in Newberg Township, Cass County, MI. We now know that Lewis, Emma, and their son, Marvin, are buried in Maple Hill Cemetery, Cadillac, Wexford Co., MI. Lewis and his sister, Lydia Ann Louisa (Clendenin) Rifenberg, are twins, according to Clendenin researchers, but it is true that Lewis' reported age in various US censuses does not necessarily support a birth year of 1850. This branch of the Clendenin family also spells their surname, Clendenen. Lewis is buried under J.S. Lewis Clendenen.