Earlier in his life, he was one of the earliest editors of the Milwaukee Sentinel in 1845, but quit after a half year to return to his legal career.

[1] He was raised and worked from his youth on his father's farm until age 19, when he entered Kimball Union Academy in New Hampshire.

[3] In February 1845, Downer purchased a share of the ownership of the Milwaukee Sentinel, becoming a partner of John S. Fillmore.

Downer began working as editor of the paper, which had just begun issuing a daily edition the prior December.

He only remained with the paper for seven months, however, resigning and selling his share of ownership in September 1845 to Rufus King.

[3] For the next 15 years, Downer distinguished himself as an attorney in Milwaukee and a member of the Whig political minority in the state.

Several candidates applied for appointment to succeed Paine, but the governor, James T. Lewis, chose Downer.

[5] Downer stood for election the next spring and won a full term on the court without facing opposition.

Although the case revolved around a technical issue, Downer's decision had the effect of extending voting rights to all African Americans in the state.