His parents were born in Pennsylvania and his father was a blacksmith who learned the practice in Rising Sun, Maryland.

Cowen attended the public schools and the local academies, including Vermillion Institute, at Fredericksburg and Hayesville, Ohio.

[1][2] Cowen commenced practice in Mansfield, Ohio, including service as prosecuting attorney of Holmes County.

He was a member of the committee on banking and currency, and was working on a plan to reorganize the nation's treasury when he resigned.

They had one daughter, Sara C.[2] In 1903, Cowen traveled to Mexico with Admiral Winfield Scott Schley, James K. Jones, Matthew Butler and Eugene Davis.