Guy Margretz was the son of Jeremiah S. Margretz. He was the grandson of Herman Henry Margretz. He was the great grandson of George Christian Frederick Margretz. He married Daisy May Derr in Iowa, 1897.180 Daisy was born in Ohio April 1880.181 She was the daughter of James Derr and Elizabeth Miller. A census listed Guy as head of household in Wilkin County, Minnesota, in 1900.182 He was listed as a 28 year-old farmer. Living with him were his wife, Daisy, 20; son, Glen, 2; and son, Vinton, 1.
He married Laura E. Wise between 1920 and 1930. Laura was born in Iowa January 1882. She was the daughter of Martin V. Wise and Adeline Strong.

Guy C. Margretz and Daisy May Derr had the following family:
i. Glenn E.5 Margretz was born March 1898.
ii. Vinton Jeremiah Margretz was born in Iowa April, 18, 1899. He married Hattie L. Feck in Iowa, between 1920 and 1925. Hattie was born March 10,1899. She was the daughter of Henry Feck and Dora --?--. Hattie died October 16,1953 in Iowa, at 54 years of age. Her body was interred in Dumont, Butler County, Iowa, at Dumont Cemetery. Vinton's occupation: police officer in Waterloo, Black Hawk County,
Vinton died June 7, 1925 in Waterloo, Black Hawk County,
Iowa, at 26 years of age. Waterloo Motor Officer Vinton Margretz was killed after losing control of his motorcycle while responding to a call for service on Fletcher Avenue. Officer Margretz died of severe head injuries. The development of modern safety helmets was still years
away and motorcycle riders of the day, typically, wore no protective headgear. His body was interred in Dumont, Butler County, Iowa, at Dumont Cemetery.
Guy died October 1938 in Mason City, Cerro Gordo County, Iowa, at 66 years of age. His body was interred in Butler County, Iowa, at Hitesville Cemetery.