Howard was born 19 February 1866, a son of John Hoover.
19 FEB 1866.
Dauphin County, Pennsylvania.
He is identified as the Howard C. Hoover, said to be age 10, who was recorded in the 1880 U.S. Census in the household of 58-year-old widow Catherine Stephenson in the borough of Dauphin, Dauphin County, Pennsylvania, and identified as Catherine's grandson. Howard was attending school and "works in Brickyard." This identification is supported by the fact that Howard Hoover had a daughter named Catherine Stephenson Hoover. Others in the household of Catherine Stephenson were daughter Mary J. Stephenson, age 20, a milliner, and granddaughter Olive A. Hoover, 9 and "at school."
As of 1891, he worked as a bridge builder. In later years he worked as a railroad flagman, brakeman, or switchman.
Howard C. Hoover died in Harrisburg, Pennsylvania, on 16 April 1954. He was buried in East Harrisburg Cemetery. 
Howard C. Hoover, age 25, of Dauphin County, married Lizzie A. Sultzbach, age 17, of Millersburg, in Dauphin County, Pennsylvania, on 3 March 1891. It was the first marriage for both. 
↑ 1.01.1 Pennsylvania Death Certificates http://interactive.ancestry.com/5164/42410_3421606191_1001-01142 Harrisburg, Dauphin County, Pennsylvania. Howard C. Hoover, died 16 April 1954. Died in hospital. Residence 2501 Hoffer St. Male, white, widowed. Switchman, P. R. R. [EDS note: Presumably the Pennsylvania Rail Road]. Born 2-19-66. Father: John Hoover. Mother: Not Known. Informant: Owen J. Hoover, Harrisburg. Cause of death: Congestive heart failure, due to coronary artery disease. Buried East Harrisburg Cemetery.
↑ 2.02.12.2Application for Marriage License No. 451. Lizzie A. Sultzbach. Female, White, Single. Age 17. Birth year 1874. Father: Jacob D. Sultzbach Marriage license date 2 Mar 1891 Marriage date 3 Mar 1891 County Dauphin, State Pennsylvania. Spouse Howard C. Hoover. Male, White, Single. Age 25. Birth year 1866. Father: John Hoover. FamilySearch film number 000021162. Marriage licence docket v. 1I-1K 1890-1892.
United States Census, 1910 Enumeration sheet for Harrisburg Ward 7, Dauphin, Pennsylvania: 1808 Wallace Street All born Pennsylvania of Pennsylvania parents Howard C Hoover 43, married 19 years, Flagman, Railroad Lizzie A Hoover 36, marriage 19 yrs, had 6 children of whom 6 are living Pearl J Hoover 18 Paul J Hoover 16 Owens J Hoover 15 Kathryn S Hoover 10 Elizabeth S Hoover 8 Amelia M Hoover 3
United States Census, 1920 Harrisburg Ward 10, Dauphin, Pennsylvania 654 Schuylkill Street Howard C Hoover 53, Switchman, Railroad Lizzie A Hoover 46 Pearl J Hoover 28, Cashier, Life insurance Owen J Hoover 24, Brakeman, Railroad Catherine S Hoover 20, Clerk, Life insurance Elizabeth S Hoover 18, Attended school; Clerk, state highway Amelia M Hoover 12, attended school
"United States Census, 1940," database with images, FamilySearch (https://familysearch.org/ark:/61903/3:1:3QSQ-G9MT-2WH9?cc=2000219&wc=QZX5-DMS%3A790227701%2C801394301%2C801596601%2C953300401 : accessed 9 April 2018), Pennsylvania > Dauphin > Penbrook Borough, Penbrook, Ward 4 > 22-107 Penbrook Borough Ward 4 bounded by (N) Canby; (E) borough limits; (S) borough limits; (W) borough limits, Hoffer S Ln, Elm > image 18 of 31; citing Sixteenth Census of the United States, 1940, NARA digital publication T627. Records of the Bureau of the Census, 1790 - 2007, RG 29. Washington, D.C.: National Archives and Records Administration, 2012.