In the Macomb Journal, 28 Dec 1898, Prairie City, MM John Heinzman of Denver are here visiting his parents, MM F Heinzman of this place.

Sold school supplies in Denver, CO.

Had no children according to my mother.

The 1900 Colorado census lists John D. Heinzman, born Oct 1862, age 37, born in Illinois with his wife Mary E, born Aug 1870, age 29, born in Iowa. Living with them are her parents and a brother-in-law. They resided at 3426 Grey St, Denver, CO, Arapahoe Co., pct 5. Census # 44,5,2.

John D. Heinzman found in genealogy.com: Family Archive #932 Census Microfilm Records: Colorado, 1900
Lived in: 6 Ward Denver, Arapahoe County, Colorado
Series: T623 Microfilm: 118 Book: 1 Page: 70

In 1910, John D. is in the Denver City Directory. He is president of Centennial School Supply Co. and resided at 125 W 12th Ave, Denver. He was renting his house.

The 1920 Colorado census lists John D. Heinzman, 57, Illinois and wife Mary E. age 49, Iowa. Ellen Bruce, her mother, is the only one living with them.

John died from Alzheimers.