Longenecker had been a farmer in Robinson, Illinois, Crawford County.[citation needed]. In the American Civil War, Longenecker, age 18, joined Co. F, 5th Regiment of the Illinois Cavalry as a private on December 4, 1864 in Olney, Illinois[citation needed]. He served for one year with no apparent distinction. [citation needed] He was prominent in such trials as the anarchist and the infamous Irish Nationalist Dr. Patrick Henry Cronin murder case. From 1899, Longenecker served as a Judge in Cook County.