Born in Cicero, New York, Dyer read law to enter the bar in 1857.

He was a member of the Wisconsin State Assembly from 1867 to 1868, returning to private practice in Racine from 1868 to 1875.

[1] On February 10, 1875, Dyer was nominated by President Ulysses S. Grant to a seat on the United States District Court for the Eastern District of Wisconsin vacated by Judge James Henry Howe.

Dyer was confirmed by the United States Senate on February 10, 1875, and received his commission the same day.

[1] Dyer was thereafter in private practice in Milwaukee, Wisconsin, and general counsel to the Northwestern Mutual Life Insurance Company from 1888 until his death on November 25, 1905, in Milwaukee.