Ancestry.com displays the pension index cards and the quality varies but
Harrison Barnum of Co. I, 22nd Mich. is clear

His mother's first name is Maria and last name I THINK is Lord but it could be Lard.
Barnum has an application number of 44199 and a pension certificate number of 32156. He was a pension.

His mother has the application #513457 but no certificate number. I don't think she was awarded a pension.

Maria's pension application should document her son's death. She would not qualify otherwise.

Harrison was about 18 when he enlisted. In 1850 US Census age matches boy living in Plymouth, Wayne county, Mich with David Barnum, carpenter, c.1819 born in New York.

The 1860 US Census has a Harrison Barnum, born about 1842 in New York working as a farm laborer in Blackman Township, Jackson County, Mich. PROBABLY same man even though estimated birth year is two years off.

Could not find a Maria Lard in any census

In 1880 Census there is a Maria Lord. c.1826 born in New York, widow living at Union city, Erie County, Pa.

The 1870 Census has Maria living with Salmon (c.1796 born) and other Lords at Richmond, Crawford County, Pa. MY GUESS--Salmon is either father or father-in-law

I noticed you can order Civil War records through a link at top of Michighan message board. Entire service/pension record about $70. Can't remember cost of pension only but with pension certificate number the researchers should find him. His pension file should summarize his service and MAY indicate year of brith and date of death.

I don't know what type of marker he has now, but he should be entitled to a free Civil War veteran's marker through the Dept. of Veteran Affairs.