John Holden Warren was born in Hogansburg, Franklin County, New York, in August 1825.

He attended the common schools in that community until age 13, when he went west to the Wisconsin Territory.

[1] He first came to Janesville, Wisconsin, when there were just two families residing there, and he attended the first school taught at that settlement.

[1] He initially established a medical practice at Lodi, in Columbia County, Wisconsin, but, at the request of his brother, abandoned his medical practice in 1851 to come to Albany, Wisconsin, in Green County, to work in the milling and mercantile business until 1870.

[3] In 1862, he was collector of internal revenue at Albany by President Abraham Lincoln, and held that office for seven years.