Hiram was a member of the U.S. Sharpshooters and served as a Major General during the American Civil War.
He was most known as the inventor of the Berdan rifle. He developed the Berdan rifle in 1868 and it was a very popular weapon with the Russian Army from 1869-1891. A second version was developed by Hiram in 1870. Over three million of these rifles were made. He also invented the center fire primer.
Berdan was considered by many to be a crack marksman and innovator.
Hiram was Commissioned an officer in Company S, U.S. Volunteers 1st Sharp Shooter Regiment on 01 Dec 1861. He was then Mustered out on 02 Jan 1864.
He was Promoted to Brevet Brig-General on 13 Mar 1865 and also on the same day was Promoted to Brevet Major-Gen on 13 Mar 1865.
1850 Census - Appears to be at a boarding house due to the large number of people in this census record:
Household Role Sex Age Birthplace
Hiram Berdan Male 26 New York
Hiram Berdan died unexpectedly on March 31, 1893 and is buried in Arlington National Cemetery. 
It appears Hiram Berdan is listed in the 1850 United States Federal Census twice.
Enumerated 17Jul1850 - Kenosha, Wisconsin, United States. Age 24. Machinist. 
Enumerated 14Oct1850 - Plymouth, Wayne, Michigan, USA. Age 26. Machinist. This entry includes others in his family. 
↑ Historical Data Systems, comp. U.S., Civil War Soldier Records and Profiles, 1861-1865 [database on-line]. Provo, UT, USA: Ancestry.com Operations Inc, 2009.Picture of Colonal Bordan
↑ 2.02.1 "United States Census, 1850," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:M4DV-DKF : 12 April 2016), Hiram Berdan in household of Eli G Runals, Kenosha, ward 1, Kenosha, Wisconsin, United States; citing family 264, NARA microfilm publication M432 (Washington, D.C.: National Archives and Records Administration, n.d.).
↑ "United States Census, 1850," database with images, FamilySearch (https://familysearch.org/ark:/61903/1:1:MF8R-7GF : 12 April 2016), Hiram Birdan in household of John Birdan, Plymouth, Wayne, Michigan, United States; citing family 410, NARA microfilm publication M432 (Washington, D.C.: National Archives and Records Administration, n.d.).
Patterson, Michael Robert. "Hiram Berdan, Major General, United States Army". www.arlingtoncemetery.net. Retrieved 28 July 2018.
Find A Grave, database and images (https://www.findagrave.com : accessed 01 January 2019), memorial page for Hiram Berdan (6 Sep 1824–31 Mar 1893), Find A Grave: Memorial #5761, citing Arlington National Cemetery, Arlington, Arlington County, Virginia, USA ; Maintained by Find A Grave .