George William Grettenberger was the son of George Jakob (1839-1897) and Katherine Elizabeth (Helwig) (1844-1918) Grettenberger. Born 9 March 1873, Meridian Township, Ingham County, Michigan, George was enrolled in Okemos Union School in 1888. He would further his literacy beyond the Okemos Union School with 2 years of high school education.

George married 16 November 1898, Lansing, Ingham County, Miss Helen B. Sherman. Helen was the only child of Manly Hard and Helen Marie (Burdick) Sherman. Manly Sherman, born in New York state, had lived in Michigan since he was a young boy and had married his wife in 1870, Ingham County. The Sherman's set up housekeeping in Meridian Township where M. H. owned and operated a fair sized general store. The Okemos store burned to the ground in October 1888. Mr. Sherman lost an estimated $3,500 ($115,700 in 2024) in the conflagration, although he did have some insurance. By the 1890's Mr. Sherman had turned to selling insurance, Michigan Accident Insurance Company, out of an office on Washington Avenue in Lansing. The insurance business turned on him when he and his wife supplied and paid up a life insurance police on an elderly distant relative. The relative died within a month of the policy being issued and the spouse, who had no idea about the policy, eventually went to the authorities and complained. Manly Sherman was arrested, bonded out on his own recogniccance. The Ingham County case was eventually dismissed with prejudice.

After George Grettenberger married Helen, he and Mr. Sherman in 1898-99 made the decison to start a grocery and druggist business in Perry, Shiawassee County, Michigan. The two couples moved to Perry and bought a house together. George and Manly worked side by side in their business while Helen and her mother maintained the home and young Helen bore a daughter, Katherine, who too would be an only child.

George was involved in local Perry Township Democratic politics and elected and served on the Perry School Board for many years. He was also an avid fisherman, joining several Okemos friends to venture on fishing trips in northern Michigan.

Manly Sherman passed away in 1920 and his wife, Helen, passed in 1921. George and Helen maintained the grocery and druggist business but by 1930 George was working the small farm he had purchased and also was employed at a local grain elevator. George accidentally broke his leg in April 1942 and complications set in. He was wheel chair bound at the time of his death, 8 September 1942, Lansing.

Helen, born 22 June 1876, Jackson County, Michigan, died 24 April 1960, Perry. She and George were interred Rose Lawn Cemetery, Perry.

Grettenberger, George (married Helen Sherman 1898) wedding announcement, The State Republican, Thursday, November 17, 1898

Sherman Manly H. (father in law of George William Grettenberger) business fire, The Lansing Journal, 8 October 1888 

Sherman Manly H. (father in law George William Grettenberger) biography, The Lansing Journal, 22 March 1895 

Grettenberger, George Jacob (father of George William Grettenberger) obit, The State Republican, Friday, December 10, 1897 

Grettenberger, George (married Helen Sherman 1898) started business in Perry, Lansing State Journal, Saturday, 21 January 1899

Grettenberger, George (married Helen Sherman 1898) Perry School board, Lansing State Journal,15 July 1915, Page 7

Grettenberger, George (married Helen Sherman 1898) Perry school board, Lansing State Journal, 13 July 1920, Page 7

Grettenberger, George (married Helen Sherman 1898) obit, Lansing State Journal, Thursday, September 10, 1942

Grettenberger, George William (married Helen B. Sherman 1898) obit, Lansing State Journal, 11 September 1942, Page 11

Sherman, Helen (married Geo. Gretternberger 1898) obit, Lansing State Journal, Monday, April 25, 1960