Myron Hickey was part of the 5th MI Cavalry according to the "Michigan in the War" book (and here from "Seeking Michigan" online). His brother, Andrew Hickey, was also found there. Myron was also in the 1st Michigan Cavalry Regiment as a major.
Myron Hickey, age 17, born in Ohio, was enumerated with his parents, M(ichael). G. & Cynthia (Wilson) Hickey in the Michigan census in 1850. Siblings included Frederick, age 19, b. NY, Andrew, 15 [died in Jackson, TN, in 1863], b. OH, Frances, 13, b. OH, George, 10, b. MI, Wilson (death record here), age 9, b. MI, Susan, age 7, b. MI, Esther, age 5, b. MI, (Benj.) Franklin, 2, b. MI, and Octavius age 10/12, b. MI. Additional information can be found in the History of Oakland County.
Myron married Hepsabeth Losee, daughter of Isaac & Mary (Davis) Losee. The Losee family was also in Oakland County, Michigan, in 1850.
Myron & Hepsabeth Hickey were found in the 1860 census taken in Oakland County, MI, here (footnote.com). No children were listed with them in that census. Myron's parents, siblings and possibly his grandmother can be found here (on footnote.com) in 1860.
Myron Hickey, b. 1833, died in Oakland Co.:
Death date: 24 Aug 1868
Death place: Springfield, Oakland, Michigan
Age at death: 35 years 7 months 4 days
Estimated birth year: 1833
Marital status: Married
Collection: Michigan Deaths 1867-1897
The widowed Hepsabeth Hickey was living in Springfield Twp., Oakland Co., Michigan, with 11 year old Myron Hickey in 1870. The article in the Lake Orion Review wondered if Myron & Hepsabeth had children. None were listed for her in the 1900 census. Hepsabeth Hickey was 85 years old and living alone in 1920 (Oakland Co., MI). It was unclear how Myron Hickey, b. 1859, was related to Hepsabeth and Myron.
Hepsabeth Hickey died 24 February 1924 at Groveland, Oakland Co., Michigan.
A Guide to Collections in the Manuscript Division of the Library of Congress (Guide To Civil War Manuscripts) has Myron Hickey listed with 41 items for the Hickey family (#433). Included are a letter from H. H. Pope to Lt. Myron Hickey 30 July 1863 regarding reconnaissance duty in LaGrange, Tennessee and deaths in Hickey's former regiment, the 5th Cavalry; letter from Myron Hickey to his family May 8, 1863, Fairfax Courthouse, Va.; and two letters from Sgt. Andrew Hickey to his brother Frederick, July 1862 and Feb. 1863 concerning campaigns in Mississippi and Tennessee. Also includes Andrew Hickey's commission as sergeant in the 3rd Michigan cavalry, Sept. 1862.
See the Archives of Michigan's Civil War Manuscripts at "Seeking Michigan" for rosters, letters, histories, etc.